C10 4.3 V6 to 350 swap

[dburbach85]

On a different note, I've been looking for a 350 TBI/TH400 transmission chip or ECM for the computer side of things and the only thing I've found is this: http://www.ebay.com/itm/121952331798?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

I don't really care about the performance, more than it doesn't mess anything up. Also, the listing says "4 speed" and I'm almost certain the TH400 is a 3 speed.

Anyone have any insights?

[Irish_Alley]

http://tbichips.com/
read this guys site. a lot more credible imo

[Stewart G Griffin]

i'm not sure what would be the best plan-----to get the 350 settled in the chassis first?    Or to worry about all the electronics?

i am pretty sure, but not 100% positive,that the injectors between the 6 and 8 are different and also the chip may need to be swapped out.   i don't have time to research right now.

i think they can help:
http://howellefi.com/

i think one one (or both) of the Howell brothers worked at GM on the original TBI system.

[Stewart G Griffin]

Actually, it's probably best i withdraw from discussing fuel injection as i don't have much experience with it.

i can still help with actually swapping the engine in though.

[dburbach85]

Thanks guys, from my research it looks like I do need the bigger injectors (already sourced) and a new 350/turbo 400 computer chip (haven't found that one yet).

I have, however, thought of some more questions.

1. Do I need a whole new radiator brace for the bigger V8 unit, or will the bigger radiator fit in the one that I have?
2. Any ideas where to find those V8 motor perches? I've so far not had any luck with that, seems that local junkyards are pretty picked over for Chevy V8 vehicles of this era.
3. Will I have any problems with the stock fuel pump supplying enough pressure for the bigger injectors?

On the build front, I picked up a well worn high-mileage TBI 350 from an early 90s Chevy truck complete with intake manifold, throttle body, and injectors for $150! Score! The motor is now at a local rebuild shop and will be coming back a new engine, then the real fun begins!

[Stewart G Griffin]

1) have no idea

2) i thought i saw some online, will pm asap.  i would give you mine but they are original to the truck.  Plus, i may want to switch back to 8 someday.

3) no idea, but probably ok since all TBI systems need about 12lbs irregardless of engine size.

[dburbach85]

Thanks for the help, and if you do come up with any sources for those perches I'd be much obliged!

[dburbach85]

Hi guys, I just wanted to say thanks for the help! It took longer than I'd hoped (what with work, family, and life) but the dying 4.3 is gone and a fully rebuilt 350 is now in place, and running nice! Thanks again!

[Stewart G Griffin]

Yay!   Good for you.  Good job.

Where did you end up getting the engine perches from?

[dburbach85]

My brother worked at a junkyard and he managed to pick some up for me. Again, thanks for the help!