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Chevy TBI engine swap

hmm, well I don't know why my post ended up as a reply to someone else's question... anyway, here it is:

Hi all, Just did a trade for an '87 Chevy 1/2 ton 4x4. It has a TBI 305 and a

4-speed manual w/granny low.

My question is, are there any changes that need to be made to the TBI to swap the engine out with a 350?

I never could figure out what the point of the 305 motor was... it has no guts to pull, yet it's not small enough to get decent fuel mileage. Oh well...

Any info would be appreciated. Thanks.

Tony Kimmell

(to email me, put a "2" after my last name in my email address)

Reply to
Tony Kimmell
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Hi!

Your original post looked fine on this end...it didn't show up under someone else's post...

William

Reply to
William R. Walsh

Tony,

Pretty sure everything is the same aside from the PROM and CALPAK chips inside the computer itself. I know the 4.3 and 5.7 injectors are different, but IIRC the 5.0 and 5.7 injectors are the same.

Doc

Reply to
"Doc"

Nope. Found out that one the hard way.

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The injectors are all the same, but they are calibrated differently, in terms of GPH, IIRC. There is a definite difference between the 5.0 and

5.7. You can tweak the screw in the center of the top to make it work, but you have to drill out the spot welds, then do a bit of trial and error, something like 1.5 turns out when going from 5.0 to 5.7. Not fun if you don't have a scan tool available. I have the actron unit and I wouldn't do it again if given the choice.

I would STRONGLY urge you to make sure the injectors, prom, calpak, and egr all come from the same donor, or are new parts to match each other. IF you buy a prom for an 87 350, get an egr for that model too, even if the engine is newer. Trust me: been there, done that, done it over.

Reply to
John Alt

Reply to
sidewinder

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