tbi 454 swap

[crewcabshorty]

I have a 1988 crew cab with a tbi 350 . I want toswap in atbi 454 . will i need to change anything to do the swap ?

[rfmaster]

Originally Posted by crewcabshorty

I have a 1988 crew cab with a tbi 350 . I want toswap in atbi 454 . will i need to change anything to do the swap ?

Yes, there a several things need to be swapped.

1) BBC TB with 80 lb-Hr injectors. The BBC TB uses 2" bores vs. 1-11/16 used by SBC TB and 62 lb-Hr injectors rated at 13 PSI. Late BBC TBI systems (94-95) used 30 PSI fuel pressure and a pair of smaller injectors. These should be avoided due to this difference - your SBC in tank fuel pump(s) can not provide 30 PSI operating pressure unless you have them replaced with aftermarket unit(s).

2) ECM EPROM - the 454 calibration is different, but the same 1227747 ECM was used with 4.3, 5.0, 5.7 and 7.4L engines in trucks. Later HD 454 used 1227787 ECM which omits knock sensor (KS) - there is little in terms of support for these ECM's - use 7747 which you have now. You can use a stock calibration or get a custom chip from various chip burners. All other sensors should transfer over. KS location on BBC is different vs. SBC. IRC there are different parts numbers for BBC KS, but I could be wrong.

3)SBC harness will have to be modified - the BBC TB uses different style IAC motor. There are two different TPS plugs styles. If you get a complete TB from JY make sure to get pig-tails!

SBC TB


BBC TB


4) If you have automatic trany - especially if it is 700R4 TV lever arm fabrication will be required. Most BBC TB throttle arms omit TV cable stud! See example below:


Please note that a stock 700R4 will NOT survive for long behind a healthy 454. Some beefing up is required - you have been forewarned.

5) Engine mounts

6) Larger radiator and shroud - get it from 454 donor.

plus other miscellaneous things that I do not recall at the moment.

//RF

[crewcabshorty]

wow, thanks for the info!

[74sqrbdy]

You will also need the 454 motor mounts and the 454 exhaust manifolds or headers.