difference in 350 TBI throttle bodies

is there really a big difference in the part numbers for the 350 TBI throttle bodies? I see several part numbers but they all pretty much look the same? is it the shape of the sensors or something?

and yes, I'm asking out of ignorance. case in point. I just picked up a 350 TBI unit part number 17087100 that shows to be 91-95 but yet shares the same part number with several others...

its not this particular one. just that this listing on ebay shows all the cross references is all. they are all pretty much the same right?

https://www.ebay.com/itm/20254959585...Bk9SR5y-t-v3YQ

also, in case you were wondering, dude just kinda tossed it in for free. I bought a pair of 454 TBI throttle bodies for $100 and he just threw the 454 intake manifolds at me and this 350 throttle body. I believe the 454 manifolds are the same as the mercruiser ones so yay to that, I can resell them to the boat guys. I should be able to maybe put the 350 injectors into the 454 throttle body and tune the ecu accordingly as well right?

dont ask why, thats a conversation by itself.

Later version with round TPS connector

Attachment 19022

Early version with flat TPS connector

Attachment 19023

Quote:

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Originally Posted by dave w

Later version with round TPS connector

Attachment 19022

Early version with flat TPS connector

Attachment 19023

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Some van and S10 throttle bodies had a throttle cam on them with a Vortec/LT1/LS1 style cable and some 4.3L and 350s also had a governor like the 2 ton trucks.

welp, I now have a pile of TBI units. I feel like a hoarder suddenly.

I got two 454 tbi units as I found they are the ones with the largest throttle bores and injectors. I have two 350 TBI units. and I have a 4.3 unit with injectors.

my 59 235 engine is closest to the 4.3 but I have been reading and seeing on past videos on youtube from others that apparently the 350 injectors work better. I dont know but I will find out. I think most of the people that tried converting a chevy 235 6 cylinder in the in the past didnt actually burn a chip. they just swapped injectors around and factory calibration chips.

I fully intend to use my chipped 7747 ecu and tuner pro to set it up properly. but at least now I have plenty of differently sized throttle bodies and injectors to play with...as well as several sets of t-body sensors and such.

I also grabbed the factory tbi bolts and a coil with bracket and bolts and an ecs and bracket with bolts, air cleaner, etc (not everything is pictured) I pretty much scavenged the entire u-pull for what I needed. so now I have pretty much an entire setup to clean up and use.

is there a way to bench test the coil itself? I have found videos on how to use a 9v battery to bench test the injectors and I see youtube videos on how to test other things...just not the coil itself...

Attachment 19033

I'd be interested in the (ISC) can off the 454 TBI. Sent you a PM.

Do they hold vacuum?

Here's a pic of the (ISC) idle speed actuator:

They can be checked wither by using a Mity vac hand pump or a hose and attach it to the hose connection and draw small amount vacuum on it by mouth. It should hold vacuum.

Swaps are generally easiest when airflow and fuel are matched to the engine. If your 235 is anywhere near stock you may want to consider using a 2.8 / 3.1 throttle body. The 4.3 calibrations have a number of compromises that other calibrations do not have and I generally recommend avoiding them as a base calibration. If you are going to use a 5.7 TB and calibration I'd recommend considering the PW at warm idle to ensure it is not too small to deliver fuel reliably. There are folks that have done the work to get the swap running well including burning chips.

You can test the coil a few different ways. Ohmmeter is easy and quick.