Hello,

I am swapping a 305 into a Volvo 740 sedan and I've decided to go with TPI. I also would like to use aluminum L98 heads not only for power, but because they put less weight over the front end. But will the EGR systems match up? I know that the Corvette heads have no exhaust gas crossover because the exhaust manifolds have tubes to carry the gases to a port on the manifold. Do the F-body systems have this provision, or will I have to find a Corvette manifold to mate to the plenum? I am considering buying a TPI system from an '85 Z28-whether or not I can adapt it to L98 heads will be the deciding factor. Also, do the L98's come in the pre '86 bolt pattern?

Thanks,

Matthew C. Hall

 

You need a Corvette intake manifold, or an aftermarket intake manifold to use the L98 heads. They have the 86 and older bolt pattern.

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West Coast GM Shootout 2001!
1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.25 @ 107.18 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-

 

baiken@hotmail.com

E-mail this guy, he has a TPI from an '86 corvette for sale.

Don>>>

 

You may be able to tap into the exhaust crossover passage in the manifold between the runners and run the pipe from the A.I.R. tube to the manifold. If you fabricate a 3-way adapter between the one way valve and the stainless steel AIR lines, and run another stainless steel line to a fabricated port in the manifold, it should work.
Also, the 85 TPI base will work with those heads.
89 Transam GTA, a few bolt ons

 

Kevin, are you saying that even the L98 heads, casting number 113, '88 and later have the old bolt pattern?

 

85 and 86 bases will work with those heads. The bolt pattern changed in 87 on the iron heads.
The aluminum vette heads have the early pre-87 intake bolt pattern.

 

Get the book Chevrolet TPI&TBI Engine Swapping by Mike Knell and distributed by JTR PO Box 66 Livermore, CA 94551.
This guy literally wrote the book on putting TPI/TBI engines into Volvo's, Jag's and everything else, he even went insane for a few days and put a F*** 302 in a Volvo!

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Rob P
89RSconvtZZ4TPI
Edelbrock Hi-Flow Intake
SLP Dual Cold Air Intake
1 5/8" Headers
Semi-Siamesed Runners
MSD6AL/relocated MAT/ AdjFPR/IROC frnt@rear swaybar/wonderbar/steeringbox/alum drvshaft/ Alston SFC/3:23posi disc rear/MAC LCA/H.Adams Panhard Rod/KYB struts/ shocks/
92Z28convt5spd
71Impala convt 402BB
BETTER DRIVING THRU SUPERIOR HORSEPOWER!

 

The L98s have no exhuast cross overs in the head. Youd have to use the vette external EGR stuff to have EGR. Yes old pattern are available.