Aside from the injectors, is there any physical difference between the TBI units from a Chevy 4.3L, 5.0L, 5.7L, or 7.4L engine?

I'm curious because they all use the same 7747 ECM's.

Can anyone clear this up?

Thanks in advance,
John

The 4.3 , 5.0 and 5.7 all use the same throttle body.....with different injectors..... the 7.4 uses a different size (bigger)
IH8mud.com (search the Landcruiser section) has good tech on TBI systems ....

Yeah, IIRC the 4.3, 5.0 and 5.7 throttle bodys use 1 11/16" bores and the 7.4 uses 2". other than that and the injectors, the other stuff is the same (there are two styles of TPS connectors)

Originally posted by Lil'John
I'm curious because they all use the same 7747 ECM's.

John

Same ECM, different "CALPACKS" i.e. ROM code is different.

If you want to play around with the calibration tables, Tuner Cat is your friend. TunerCat FAQs here (http://www.tunercat.com/tnr_desc/do_tc.html) :D

Tom :usa:

Cool... thanks for the good info.

Now I'll have to go track down the elusive 7.4L TBI unit :P