1978 GMC P15 Automatic Transmission Kits
Keep Your 1978 GMC P15 in Top Shape with Quality Automatic Transmission Kits
Whether you’re repairing or upgrading your Automatic Transmission Kit, using high-quality parts is key to keeping your 1978 GMC P15 looking sharp and performing at its best. At Advance Auto Parts we carry a wide selection of dependable options, including Transmission Master Repair Kits, Transmission Shift Kits, and Transmission Rebuild Kits. Whether you’re replacing a damaged part or enhancing your truck’s style and protection, you’ll find exactly what you need to get the job done right.
Competitive Prices and Extensive Inventory
The average price for a 1978 GMC P15 Automatic Transmission Kit at Advance Auto Parts is around $239.74, with a range that starts at $73.99 and goes up to $511.99. With 16 options in stock from 3 trusted brands, finding the right fit is easy. Popular picks like Automatic Transmission Banner Repair Kit, Automatic Transmission Master Repair Kit, and Automatic Transmission Master Repair Kit Plus start at just $179.99 and offer a great balance of form and function.
Explore Related Parts
While you’re upgrading or replacing your Automatic Transmission Kit, don’t forget to check out other key components like Torque Converter and Related Products and Transmission Cooler and Parts. At Advance Auto Parts, we’re here to help you keep your 1978 GMC P15 in peak condition, inside and out.
Find Your Specific 1978 GMC P15 Automatic Transmission Kits
Looking for the perfect Automatic Transmission Kit for your 1978 GMC P15? You’re in the right place. Below, you’ll find links to various types of Automatic Transmission Kits that fit your vehicle. At Advance Auto Parts, we offer only the highest quality OEM and aftermarket Automatic Transmission Kits, ensuring durability and a precise fit for your GMC P15. Whether you’re driving a 1978 model or another popular model year like
1975,
1976, and
1977, we’ve got you covered. Purchasing Automatic Transmission Kits from Advance Auto Parts is a smart choice, giving you access to trusted brands and parts built to perform. Below, you’ll find links to various types of Automatic Transmission Kits that fit your vehicle.
Essential 1978 GMC P15 Automatic Transmission Kits
ATP – Automatic Transmission Shift Kit (Part No.JK-1)
B & M – Transmission Kit, Master Overhaul Kit For TH400 (Part No.21041)
from
$459.99
These kits include all of the necessary components to rebuild your automatic transmission. OEM style gaskets included. Kits do not include overhaul instructions – please refer to factory shop manual for proper assembly procedures.
Product Features:
See More
Product Features:
- Complete High Perf. Or Racing Trans. Overhaul
- Includes Only OEM Valvebody Gaskets
- Instructions Not Included
B & M – Transpak For 68-81 TH 350 Transmission (Part No.30228)
from
$166.99
The B&M Transpak has all the features in the Shift Improver Kit, plus it provides additional driver manual control. Retain full automatic features and standard shift points with selector in Drive.
Product Features:
See More
Product Features:
- Recalibrate Auto. Transmission
- Optimum Performance
- Select Your App. Mode
- Improves Transmission Life
- Trans. Removal Not Required
B & M – Shift Improver Kit For 65-87 TH400 Transmission (Part No.20260)
from
$73.99
The B&M Shift Improver Kit the easiest way to get the performance you’ve always wanted out of your automatic transmission, two modes to select from: Heavy Duty, or Street/Strip. It’s our least expensive and simplest to install kit.
Product Features:
See More
Product Features:
- Provides Crisp Shifts
- On Any Stock Automatic Transmission
- Eliminates Soft/Sluggish Shift
- Eliminates Shift Overlap
- Eliminate Clutch and Band Wear
- Improves Transmission Life
- Transmission Removal Not Required
ATP – Automatic Transmission Banner Repair Kit (Part No.JM-10)
from
$179.99
When it’s time to rebuild an automatic transmission, it’s a big job. ATP Automatic Transmission Banner Repair Kits come with friction plates, seals, o-rings, gaskets, And sealing rings. ATP components are engineered to fit And function just like the original parts for long life And durability.
See More
B & M – Transmission Kit, Transkit 68-81 TH-350 Transmission (Part No.30229)
from
$459.99
B&M Transkits give you the same high-quality components that are used in all B&M Street and Strip transmissions. They also include special directions on how to modify your case, pump, and components.
Product Features:
See More
Product Features:
- High Perf. Friction Materials
- Complete Overhaul Gasket Set
- Modification Components
- Replacement Valves
- Replacement Springs
ATP – Automatic Transmission Overhaul Kit (Part No.SGS-27)
from
$89.99
When it’s time to rebuild an automatic transmission, it’s a big job. ATP Overhaul Kits come with seals, o-rings, gaskets, And sealing rings. ATP components are engineered to fit And function just like the original parts for long life And durability.
See More
ATP – Automatic Transmission Overhaul Kit (Part No.JGS-52)
from
$81.99
Automatic Transmission Overhaul Kit
B & M – Transkit For 65-87 TH400 Transmission (Part No.20229)
from
$511.99
A B&M transmission in a box! Transform your automatic transmission into a full-tilt B&M performer! This is our ultimate transmission kit – it comes complete with full instructions on how to assemble your transmission to B&M specifications.
Product Features:
See More
Product Features:
- High Perf. Friction Materials
- Complete Overhaul Gasket Set
- Modification Components
- Replacement Valves
- Replacement Springs
- Drain Plug Kit Included
ATP – Automatic Transmission Overhaul Kit (Part No.SGS-28)
from
$102.99
When it’s time to rebuild an automatic transmission, it’s a big job. ATP Overhaul Kits come with seals, o-rings, gaskets, And sealing rings. ATP components are engineered to fit And function just like the original parts for long life And durability.
See More
ATP – Automatic Transmission Banner Repair Kit (Part No.SM-11)
from
$206.99
When it’s time to rebuild an automatic transmission, it’s a big job. ATP Banner Kits come with friction clutch plates, seals, o-rings, gaskets, And sealing rings. ATP components are engineered to fit And function just like the original parts for long life And durability.
See More
ATP – Automatic Transmission Master Repair Kit Plus (Part No.JMS-9)
from
$393.99
ATP Master Repair Kit Plus contains friction And steel clutch plates, gaskets, seals, o-rings, sealing rings, sump filter, And commonly replaced bushings required to high quality transmission rebuilding.
See More
ATP – Automatic Transmission Master Repair Kit (Part No.SM-9)
from
$276.99
ATP Master Repair Kits contain friction And steel clutch plates, gaskets, seals, o-rings, sealing rings, And commonly replaced bushings required for complete transmission rebuilding.
See More
ATP – Automatic Transmission Master Repair Kit (Part No.JM-9)
from
$269.99
When it’s time to rebuild an automatic transmission, it’s a big job. ATP Master Repair Kits come with friction And steel clutch plates, seals, o-rings, gaskets, And sealing rings. ATP components are engineered to fit And function just like the original parts for long life And durability.
See More
B & M – Master Overhaul Kit, TH350 Transmission (Part No.21042)
from
$385.99
The Master Racing overhaul kits are supplied with all of the gaskets, seals, bushings, and friction material required for a complete high performance or racing trans overhaul. Does not come with transbrake gaskets or components.
Product Features:
See More
Product Features:
- Complete High Perf. Or Racing Trans. Overhaul
- Includes Only OEM Valvebody Gaskets
- Instructions Not Included
Popular 1978 GMC P15 Automatic Transmission Kits Categories
Most Popular Transmission Master Repair Kits for 1978 GMC P15s
Enhance your 1978 GMC P15 with one of the 4 Transmission Master Repair Kits we have in stock, starting at just $269.99.
ATP – Automatic Transmission Master Repair Kit Plus (Part No.JMS-9)
from
$393.99
ATP Master Repair Kit Plus contains friction And steel clutch plates, gaskets, seals, o-rings, sealing rings, sump filter, And commonly replaced bushings required to high quality transmission rebuilding.
See More
ATP – Automatic Transmission Master Repair Kit (Part No.JM-9)
from
$269.99
When it’s time to rebuild an automatic transmission, it’s a big job. ATP Master Repair Kits come with friction And steel clutch plates, seals, o-rings, gaskets, And sealing rings. ATP components are engineered to fit And function just like the original parts for long life And durability.
See More
B & M – Master Overhaul Kit, TH350 Transmission (Part No.21042)
from
$385.99
The Master Racing overhaul kits are supplied with all of the gaskets, seals, bushings, and friction material required for a complete high performance or racing trans overhaul. Does not come with transbrake gaskets or components.
Product Features:
See More
Product Features:
- Complete High Perf. Or Racing Trans. Overhaul
- Includes Only OEM Valvebody Gaskets
- Instructions Not Included
ATP – Automatic Transmission Master Repair Kit (Part No.SM-9)
from
$276.99
ATP Master Repair Kits contain friction And steel clutch plates, gaskets, seals, o-rings, sealing rings, And commonly replaced bushings required for complete transmission rebuilding.
See More
Best-Selling 1978 GMC P15 Transmission Shift Kits
Upgrade your P15 with one of our 4 best-selling Transmission Shift Kits.
B & M – Transmission Kit, Master Overhaul Kit For TH400 (Part No.21041)
from
$459.99
These kits include all of the necessary components to rebuild your automatic transmission. OEM style gaskets included. Kits do not include overhaul instructions – please refer to factory shop manual for proper assembly procedures.
Product Features:
See More
Product Features:
- Complete High Perf. Or Racing Trans. Overhaul
- Includes Only OEM Valvebody Gaskets
- Instructions Not Included
B & M – Transpak For 68-81 TH 350 Transmission (Part No.30228)
from
$166.99
The B&M Transpak has all the features in the Shift Improver Kit, plus it provides additional driver manual control. Retain full automatic features and standard shift points with selector in Drive.
Product Features:
See More
Product Features:
- Recalibrate Auto. Transmission
- Optimum Performance
- Select Your App. Mode
- Improves Transmission Life
- Trans. Removal Not Required
ATP – Automatic Transmission Shift Kit (Part No.JK-1)
B & M – Shift Improver Kit For 65-87 TH400 Transmission (Part No.20260)
from
$73.99
The B&M Shift Improver Kit the easiest way to get the performance you’ve always wanted out of your automatic transmission, two modes to select from: Heavy Duty, or Street/Strip. It’s our least expensive and simplest to install kit.
Product Features:
See More
Product Features:
- Provides Crisp Shifts
- On Any Stock Automatic Transmission
- Eliminates Soft/Sluggish Shift
- Eliminates Shift Overlap
- Eliminate Clutch and Band Wear
- Improves Transmission Life
- Transmission Removal Not Required
Top-Quality Transmission Rebuild Kits for 1978 GMC P15s
Choose a high-quality OEM or aftermarket Transmission Rebuild Kit for GMC P15s and enjoy top-notch performance from $81.99.
ATP – Automatic Transmission Banner Repair Kit (Part No.JM-10)
from
$179.99
When it’s time to rebuild an automatic transmission, it’s a big job. ATP Automatic Transmission Banner Repair Kits come with friction plates, seals, o-rings, gaskets, And sealing rings. ATP components are engineered to fit And function just like the original parts for long life And durability.
See More
ATP – Automatic Transmission Overhaul Kit (Part No.JGS-52)
from
$81.99
Automatic Transmission Overhaul Kit
B & M – Transkit For 65-87 TH400 Transmission (Part No.20229)
from
$511.99
A B&M transmission in a box! Transform your automatic transmission into a full-tilt B&M performer! This is our ultimate transmission kit – it comes complete with full instructions on how to assemble your transmission to B&M specifications.
Product Features:
See More
Product Features:
- High Perf. Friction Materials
- Complete Overhaul Gasket Set
- Modification Components
- Replacement Valves
- Replacement Springs
- Drain Plug Kit Included
B & M – Transmission Kit, Transkit 68-81 TH-350 Transmission (Part No.30229)
from
$459.99
B&M Transkits give you the same high-quality components that are used in all B&M Street and Strip transmissions. They also include special directions on how to modify your case, pump, and components.
Product Features:
See More
Product Features:
- High Perf. Friction Materials
- Complete Overhaul Gasket Set
- Modification Components
- Replacement Valves
- Replacement Springs
ATP – Automatic Transmission Banner Repair Kit (Part No.SM-11)
from
$206.99
When it’s time to rebuild an automatic transmission, it’s a big job. ATP Banner Kits come with friction clutch plates, seals, o-rings, gaskets, And sealing rings. ATP components are engineered to fit And function just like the original parts for long life And durability.
See More
ATP – Automatic Transmission Overhaul Kit (Part No.SGS-28)
from
$102.99
When it’s time to rebuild an automatic transmission, it’s a big job. ATP Overhaul Kits come with seals, o-rings, gaskets, And sealing rings. ATP components are engineered to fit And function just like the original parts for long life And durability.
See More
USA Standard Gear – Manual Transmission Bearing and Seal Overhaul Kit (Part No.76455)
from
$92.99
Manual Transmission Bearing and Seal Overhaul Kit
ATP – Automatic Transmission Overhaul Kit (Part No.SGS-27)
from
$89.99
When it’s time to rebuild an automatic transmission, it’s a big job. ATP Overhaul Kits come with seals, o-rings, gaskets, And sealing rings. ATP components are engineered to fit And function just like the original parts for long life And durability.
See More
FAQs for 1978 GMC P15 Automatic Transmission Kits
What are the best-selling Automatic Transmission Kits for 1978 GMC P15s?
Out of 16 Automatic Transmission Kits that fit 1978 GMC P15s, the following parts are the top sellers:
- Automatic Transmission Banner Repair Kit (11238675) – $179.99
- Automatic Transmission Master Repair Kit (11238799) – $269.99
- Automatic Transmission Master Repair Kit Plus (11238803) – $393.99
What’s the price range for 1978 GMC P15 Automatic Transmission Kits?
The prices of Automatic Transmission Kits for the 1978 GMC P15 range from $73.99 up to $511.99 for the most premium parts.
What is the average price of an Automatic Transmission Kit for a 1978 GMC P15?
The average price for Automatic Transmission Kits for the 1978 GMC P15 is $239.74. Keep in mind the variety of part types within our Automatic Transmission Kit category, where you are likely to find a wide range of prices across a variety of parts and components.
Does Advance Auto Parts sell Automatic Transmission Kits for other GMC P15 model years?
What are the cheapest Automatic Transmission Kits for my 1978 GMC P15?
The cheapest 1978 GMC P15 Automatic Transmission Kits we carry are:
- Shift Improver Kit For 65-87 TH400 Transmission (6121209) – $73.99
- Automatic Transmission Shift Kit (11239173) – $80.99
- Automatic Transmission Overhaul Kit (11238741) – $81.99
- Automatic Transmission Overhaul Kit (11238824) – $89.99
- Manual Transmission Bearing and Seal Overhaul Kit (12009776) – $92.99
Does Advance Auto Parts sell Automatic Transmission Kits for any other 1978 GMC models?
Yes. We stock Automatic Transmission Kits for 12 other popular 1978 GMC models. Some of the most popular are 1978 Jimmy Automatic Transmission Kits, 1978 Caballero Automatic Transmission Kits, 1978 K25 Automatic Transmission Kits, 1978 K15 Automatic Transmission Kits, and 1978 G25 Automatic Transmission Kits.
What types of Automatic Transmission Kits do you sell for my 1978 GMC P15?
As of 6/2/26, these are some of the most in-demand types of Automatic Transmission Kits for a 1978 GMC P15:
Can I get help with 1978 GMC P15 Automatic Transmission Kit orders?
Contact our customer support team by chat or phone, through the help desk page, where you can find instant answers about GMC Automatic Transmission Kits and more.
What is your return policy for GMC P15 Automatic Transmission Kits?
Advance Auto Parts keeps returns simple. For new GMC P15 Automatic Transmission Kits and accessories, your online orders can be returned, in their original condition, within 45 days. For requirements, see the returns page.