Small block to big block TBI
 

I have an 87 1/2 ton, 305ci in my 4x4 that is going south and have a 454 big block that I might put in its place. The question? Did the big blocks of that era have the TBI or were they all carburated? Just wondering what I would have to do to put the big block in. I also have an older 350 that I could throw in if its too much of a hassle to go big block with that set-up? I'm sure someone has had this dilema before?

Re: Small block to big block TBI
 

Hey Bstack

In 87, C30 was available with 454 TBI.
You have to check your local smog laws, but I think a straight over swap should be OK provided that you keep all smog equipment operation per mfg specs ( it is in Cali). Save all smog labels from donor truck! It would be a good idea to have a complete donor 454 TBI with ECM and sensors to swap over.
You can probably re-use your 305 ECM - (my guess it is 1227747), but only if you replace MEMCAL to match 454 requirements, as well as resistor pack for a ‘limp back’ mode. This will require some soldering inside your 305 ECM
ESC and knock sensor are different for 454. Check your fuel pump, and better replace it with a high volume unit (Walbaro, etc).
305 TBI injectors are too small for 454 CID application, also 454 TBI body uses 51mm throttle body (2") diameter. Small block TBI is smaller.

Re: Small block to big block TBI
 

Thanks for the reply rfmaster. I'm kinda ignorant of TBI talk, what is the ECM and memcal? Thanks again

Re: Small block to big block TBI
 

i have a running 87 suburban auto with a bb tbi that i am going to part out,make me an offer on the tbi stuff, wiring, computer.im about 3.5 hours from you in wv.

Re: Small block to big block TBI
 

Bstac

If you are going to do TBI 454 swap I would strongly suggest to get 'very' familiar with TBI system. A good backgrounder can be found here:

http://www.binderbulletin.org/forums...ad.php?t=45292

ECM-engine control module
ESC-electronic spark control.
MEMCAL-Memory Calibration Unit contains engine specific calibration information.

Re: Small block to big block TBI
 

Tommy, PM Sent