Vinscully50

I have an 86 IROC Z with an LB9. A few weeks ago, I got a free second set of TPI runners, a plenum and a base from a family friend. However, they are off of an 89 L98 out of an 89 Corvette. The friend pulled the L98, took off the TPI and converted the short block to Carb for an old Drag Truck project.
I planning on porting these and want to know if I can throw it on my LB9 with my stock heads?

Tuned Performance

iTrader: (92)

The corvette base has center holes at 90 degrees. 86 should be 72. Just elongate the center holes for it to bolt up.

stew'86MCSS396

Does CSI come into play with the latter setup???

Tuned Performance

iTrader: (92)

CSI was 85-88 the provision is there on 89 & 90-92 bases but the runner blocks the unused hole.

Kevin91Z

iTrader: (1)

Really? I thought the 85-91 TPI Corvettes all used the same bolt style, the 86-earlier. The 87-92 Camaro/Firebird used the 72* center bolt holes. So I would think a Corvette manifold would fit an 86 with no problem.

Airwolfe

iTrader: (1)

The small block Chevy V8 engine got a one piece rear main seal in 1986, provisions for a roller tappet camshaft in 1987, center bolt valve covers in 1987, in 1987 the angle changed on the center two bolts on each side on the intake manifold and the cylinder heads except for the Y body Corvette. Corvettes kept the traditional bolt angles on the intake manifold and cylinder heads until 1991.

The Y body Corvette cylinder heads and lower intake manifold don't have provisions for exhaust gas cross over for the EGR system. The exhaust gas for the EGR system is supplied by a pipe running from the passenger side exhaust manifold/header to a port on the back of the lower intake manifold.

The computer controlled large cap HEI distributor was changed to a computer controlled small cap external coil HEI in 1987 except for the Y body Corvette which kept the computer controlled large cap HEI distributor until 1991.

For 1989 the Cold Start Injection system was eliminated, the Rochester Products Multec fuel injectors were introduced, the throttle body and throttle body gasket was changed, the upper plenum was changed to match the revised throttle body and gasket, the throttle linkage was changed along with the throttle cable. The 1989+ throttle body with its revised throttle linkage is smoother when transitioning from idle to part throttle. The TPI runners were changed due to the removal of the Cold Start Injection system. There are probably some other subtle changes I have forgot about.