400 TBI, 4X4High

[SUBFAN]

I have heard of two instances of people doing this....One was on here and the other was second hand info locally.

I locked up the 350, and the cheapest easiest fix is to take the 400 short block I have and put on the TBI upper end and stuff it back in there.

I have some concerns about:

Where the compression ratio is going to end up....

Is it going to flip the computer out????

This combination will be (hopefully) temporary while I resume the search for a BBC....

 

[Hossbaby50]

The cam would be the biggest question I think to whether it would work or not. If the cam is even a little wild you might have problems.

Harley

 

[SUBFAN]

I was going to keep it mild, as the most tricked out SBC will not equal the performance of the BBC....

Yes I know about the steam holes too....LOL

 

[4X4HIGH]

You will need to have a chip burned. The fuel and timing curves won't be correct for a 400 to run correctly. Do't get me wrong, it will run but probably like crap and run lean and start to detonate or ping.

 

[dyeager535]

I know people run 400's with various types of injection, one thing you will want to look into as well as a new PROM, is the knock sensor. They are different based on displacement, (305 and 350 are different for instance) and if it ends up thinking the engine is pinging all the time, it will reduce performance as well.

Must be a fairly easy workaround, thirdgen.org has a pretty extensive TBI section that might give you some ideas on what is needed to go from 350-400 with TBI.

 

[SUBFAN]

I will check that out....Right now I am just going to run the old trusty 3310

 

[rjfguitar]

If it was me I would get a 454 throttle body and computer chip if you can. I would be that would flow enough fuel for a mild 400. All I know is that you don't want to lean out a 400 because you will never get it to quit pinging, don't ask me how I know.