1980 C15 Swap

[T.Markel]

I have an '80 GMC C15 that had the 5.7 Diesel originally, and has had a small block 350 put in and was told that the Torque Converter was the original and should be changed. Do I need to change the converter, and what options are out there if I really do need this?

Transmission is a TH350

any feedback is greatly appreciated.

 

[bucket]

Are you happy with how the truck drives? Is it doggy from a start or is the engine fighting the brakes when you are stopped and in gear?

 

[T.Markel]

Are you happy with how the truck drives? Is it doggy from a start or is the engine fighting the brakes when you are stopped and in gear?

It drives decent.. not doggy by any means, pretty quick and all too easy to start spinning tires.. but it kind of sounds like it's running somewhat high rpm at 60-65 mph. maybe it's just me, I just got it and haven't really driven it very much yet. looking into buying a tach just to see what it says..

 

[HotRodPC]

Welcome to GMSB Troy. I had one of those too. It also was an 80 that was originally a 5.7 Olds Diesel, and then converted to 350 Olds Gas. So did they convert yours to Small Block Chevy or did they bolt in a 350 Olds Gas motor? A couple advantages you should have, HydroBoosted power brakes instead of Vac Boost, and 2 battery trays so a dual battery set up with battery isolator is an easy upgrade.

If you're happy with the way it runs, I'd rock on with what you got. If the rpms seem a bit high on the highway, chances are you have a good gear ratio, like a 3.42 or 3.73. Mine came with a 3.08 which was a sled off the light.

 

[89Suburban]

Welcome aboard.

 

[bucket]

If you're happy with the way it runs, I'd rock on with what you got.

Agreed! If it ain't broke, don't fix it

 

[T.Markel]

Welcome to GMSB Troy. I had one of those too. It also was an 80 that was originally a 5.7 Olds Diesel, and then converted to 350 Olds Gas. So did they convert yours to Small Block Chevy or did they bolt in a 350 Olds Gas motor? A couple advantages you should have, HydroBoosted power brakes instead of Vac Boost, and 2 battery trays so a dual battery set up with battery isolator is an easy upgrade.

If you're happy with the way it runs, I'd rock on with what you got. If the rpms seem a bit high on the highway, chances are you have a good gear ratio, like a 3.42 or 3.73. Mine came with a 3.08 which was a sled off the light.

Its a small block chevy 350, Crane Energiser 260 cam, HEI, edelbrock 600 CFM Performer carb.. I bought a set of Vortec heads that will go on when I buy the vortec style intake. just waiting on the funds...