Small Block & Big Block Chevy Specific - 88 TBI SBC Swap to 85 SBC intake question




TrickyTransAm
09-02-2007, 07:54 PM
I'm helping a co-worker do a swap on a truck he recently purchased.

1988 GMC Sierra SLE, with a 350 TBI engine, center bolt style heads.
The engine is literally pumping oil and coolant out the tailpipe, and we have another engine we want to swap in.

The other engine is a 85? or so 350 SBC carbureted, with 4 bolt (traditional) valve cover mounts.

What I would like to do, is bolt the TBI intake on the 85ish Motor.
I hear the TBI intake mount bolt angles are different going into the head.

Can this be done with minor modifications, or is there a whole lot more to it?

Thanks for any adivce you can provide.
C


whytryz28
09-03-2007, 07:11 PM
Yup like you said you cant bolt the TBI intake to the 85 or earlier head. You would have to tansfer the heads and intake for it to work.

redbandit98
09-03-2007, 08:13 PM
na they make adapters for the bolt holes. They can either be used to put an older intake on a newer motor or vice versa.


whytryz28
09-03-2007, 08:22 PM
Adapters? Wouldnt you be shortening the intake then if you need to space it from the head to fit a bolt? I wouldnt trust any quick fix.

Street Lethal
09-06-2007, 02:44 AM
What I would like to do, is bolt the TBI intake on the 85ish Motor. I hear the TBI intake mount bolt angles are different going into the head. Can this be done with minor modifications, or is there a whole lot more to it?

You will need to elongate the bolt holes on the TBI intake manifold.... ;)

8a8mfh
09-06-2007, 09:28 AM
You will need to elongate the bolt holes on the TBI intake manifold.... ;)

Thats right, take a drill and elongate the four center holes. The intake will fit right on.

Theres no sense in using heads off an engine thats puking oil and coolant.

mzoomora
09-06-2007, 09:38 AM
na they make adapters for the bolt holes. They can either be used to put an older intake on a newer motor or vice versa.
When you buy the China made intakes that Summit sells, and on eBay they come with the adapters. The holes in the center are larger for the adapters to fit in. Even if you elongate the holes the angle of the bolts is different and they dont sit on the intake right. It does work though and has been done plenty of times with success.

If you read the description for this intake they mention the adapters, and you can see how big the holes are for them to fit in. It is just a bushing that fits in the hole and the top of it has a seat that corrects the angle.
http://cgi.ebay.com/ebaymotors/PROFESSIONAL-PRODUCTS-57-95-SBC-CHEVY-INTAKE-MANIFOLD_W0QQcmdZViewItemQQcategoryZ36474QQihZ011Q QitemZ320146435562QQrdZ1QQsspagenameZWD1V

redbandit98
09-06-2007, 11:59 PM
thats what i was referring to. I acutally have some of them laying around somewhere. If you want to go old to new pop them in, if you are going the other way, flip them over and use them.

for what its worth, i have a set of freshly rebuilt centerbolt heads. completley gone through with new seals, and everything else they needed. My buddies dad is the head man at the machine shop so he did me right on them. ill let them go for 200 plus shipping. was gonna use them on a new shortblock but went ahead and bought a crate motor.