New Engine

[Schurkey]

Remember that the automatic transmissions used behind V6 applications had fewer clutches in the clutch packs, and therefore a lower torque limit. They may be programmed to shift at different shift-points, also.

You'll get by with a V6 trans...for awhile.

If you can find a '91--'93 5.7L TBI Caprice/Roadmaster/Brougham engine, they have flat-top pistons instead of dish, and roller cam instead of flat-tappets. I had one in my '88 K1500 for almost two decades. They're good for a very minor power improvement (not much.)

 

[df2x4]

Remember that the automatic transmissions used behind V6 applications had fewer clutches in the clutch packs, and therefore a lower torque limit.

Is this true on into the '96+ trucks? If so that might be a contributing factor to my abysmal luck with 4L60Es in my V6 truck.

 

[L31MaxExpress]

Is this true on into the '96+ trucks? If so that might be a contributing factor to my abysmal luck with 4L60Es in my V6 truck.

Any builder with their keep should upgrade a HD application to the V8 spec. I have pulled apart several CPI 4.3 transmissions that had never been opened that had a V8 clutch count. From what I remember it has a thicker steel or wave plate and one less 3-4 clutch pack. In the newer stuff the Vette has a wider band and the 65/70E has 5 pinon planets. Also keep in mind GM engineers felt the 60E was too weak to use in the 3/4 ton vans with a 4.3 and used an 80E behind those. The older G30s with a 4.3 also had a 4L80E. A whole 155 hp V6 with an 80E behind it.

 

[df2x4]

Any builder with their keep should upgrade a HD application to the V8 spec.

That was my thought as well, I was more curious in regard to the original 60E that came in my truck.

And thank goodness for the 4.3/80E vans, the fact that those existed made my 80E swap into my 4.3 truck much easier. Not only the base tune, but I sourced a lot of random stuff like the inspection cover by looking at van parts diagrams.

Sorry for hijacking your thread domcan1000, just had to ask.

 

[L31MaxExpress]

That was my thought as well, I was more curious in regard to the original 60E that came in my truck.

And thank goodness for the 4.3/80E vans, the fact that those existed made my 80E swap into my 4.3 truck much easier. Not only the base tune, but I sourced a lot of random stuff like the inspection cover by looking at van parts diagrams.

Sorry for hijacking your thread domcan1000, just had to ask.

I tuned an 01 GMT800 4.3 truck with a Black box a few years ago. The guy had swapped in an 80E. I segment swapped 4L80E trans segments into his stock PCM. Used the trans tune out of a cut-away box van that had a 350. The PCM operating system happened to match. Left all the shifting alone. Drove like it came from the factory with a 4L80E. It was a RCSB, still had every bit as much power as it did with the 60E.

 

[domcan1000]

Lol that's ok I didn't realize the transmission would be different. If it will last me a year I'll be ok. I'm trying to get the truck ready for my wedding next year so I need it to last until then.

All of this information is really helpful I'm trying to price everything out so that I can see how much of the budget it will take. Thank you everyone.

 

[fancyTBI]

If you can find a '91--'93 5.7L TBI Caprice/Roadmaster/Brougham engine, they have flat-top pistons instead of dish, and roller cam instead of flat-tappets. I had one in my '88 K1500 for almost two decades. They're good for a very minor power improvement (not much.)

This is what I put in mine. I like it, nice smooth engine. Glad to see someone else who did it long before me.

 

[domcan1000]

Trying to put together a list of things to grab at the local yard. Should I get injectors from a truck in the yard, rockauto, lmc, or somewhere else?

Can I get the ecu from a yard truck?

What about motor mounts? I see rockauto has them for up to $10 but then the acdelco one skyrockets to $49. I assume the cheaper ones will suffice.

I also was trying to look into a caprice but didn't find anything locally.

I am going to try to get a mark 8 fan to swap while im working on all of this also.

I have one more question for now and I have been trying to figure it out but haven't been able to wrap my head around it. Should I change the rear gears? I believe I have 3.08 and I have 265/60/18 tires but I don't know how to calculate whether they would need to be changed or not.

Thanks to everyone!

 

[fancyTBI]

I left my 3.08 the same. Still enough go for me. Your preference might vary. I’m sorry I forgot the list of compatible ECUs, I have the excel file at home. Let me PM you the file tonight. I think I ordered motor mounts through Summit.

From the yard truck, grab all the brackets on the intake you can. Some of them are different. Like the throttle cable bracket, and the coil bracket is different too. It sits in a different spot. I think the stuff that holds the MAP, etc. is the same. Don’t quote me. If it’s cheap, just grab it.

 

[domcan1000]

That would be awesome I really appreciate it!

Ok I will see what I can find I think I will leave the gears for I really just want to get it running.

Also, is there any other mods I should do while all of this is going on?