89RsPower!

Are there differences between an 86 and 89 lower intake? The reason I ask is I have the lower sittin around from my 86 vette, and the 89 currently bolted to my IROC, next weekend I'm doing an engine swap and I already have the 86 lower ported and shined up.. basically it would be easier to just bolt that one on and clean up the 89 lower later.. but if they are different i'll just wait until I get the 89 lower off I suppose.. thanks!

TIMMYS89GTA

iTrader: (28)

one difference.
The 86 has the cold start injector and the 89 does not.
The 86 will work if you make a block off plate for the CSI

8Mike9

I'm pretty sure that the CSI issue is only in the runner, not the lower intake.

Only difference I know from '86-older vs 87-newer is the ceneter for intake holes are angles differently for the newer Center bolt (083/ie) heads...The Vette intakes were all the same , IIRC, with the older converntional style intake angles.

You can slot the holes, and it's best to run the angled/beveled washers to ensure good seal/contact of the bolts. Aftermarket intakes usually have things milled for both and different washers are not needed.

89RsPower!

yeah I know the cold start injector bolts into the runner on the drivers side but I'm not sure if the port the runner bolts to is different or not, forgot about the bolt angle difference.. maybe I'll just wait and clean up the 89 base..

8Mike9

The port is the same, you can slot the intake holes with a drill bit if you're real careful, but best to use a diegrinder/dremmel...the Al peels off pretty quick and if you get a little overzealous, you wind up with a big hole...don't ask me how I know

But definitely if you slot the holes, get the beveled washers/shims, Accel/Mr. Gasket used to carry them.

TIMMYS89GTA

iTrader: (28)

Oh yeah DUH!
Don't know what I was thinking about.
89rspower,you might want to wait and do the 89 intake later after all.

Dens71TA

iTrader: (5)

The 'Vette intakes are setup for an external EGR feed off the exhaust manifold since the 'Vette heads didn't have an exhaust crossover. The port is right next to the distributor opening. F-body intakes fed the EGR through the usual exhaust crossover in the head.

I would wait and clean up the '89 base.

89RsPower!

the egr is a good point, though not valid in my case, my 86 was an early build, the first half of 86 vettes were iron headed, they didn't switch to al heads until mid way through the year.

billydonn

I would use the 86. As far as flow goes you can switch the manifolds... all that other stuff (bolt holes etc.) aside, the flow of all the tpi manifolds in stock form is the same.