Has anybody tried to modify the center bolt holes on a stock TPI base to make them fit the older style heads?? Are there any ways around this?

 

Just take a drill and make them slotted like all the aftermarket baseplates are.

-- Joe

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/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
1989 Formula 350 4-bolt mains, Forged .030 TRW pistons, SLP 51010 Roller Cam, Comp-cams roller lifters,
Summit 1.5 roller rockers, World Products Sportsman II 2.02/1.60 heads, Edelbrock TPI Intake,
Cloyes Double Roller, timing chain, Mellings oil pump: 13.5 @ 100.23 MPH

Since close of track : Ported SLP runners, Ported Plenum, AFPR, Autometer 100lbs gauge, A/F ratio gauge.

http://www.joesperformance.com

 

I have done several older intakes to fit newer heads, I'm sure its just as easy the other way around. Just keep elongating untill the center bolts can be threaded easily by hand into the heads. You don't want to make the whole too big, but you don't want the bolt to bind and cause the manifold to not sit correctly or clamp unevenly.

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If you live in Southeastern US, check us out!
South East Thirdgen

1987 Trans Am 305
14.88 @ 92.81

[This message has been edited by GMTech (edited November 25, 2001).]

 

Thanks.....time to take those swirlie heads off!

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91 Z-28 L-98 G-92 Edelbrock TES, Flowmaster catback(where the cat used to be anyhow!) Accel module and coil, air foil, AFPR, mild porting in plenum Hypertech chip runs 14.40 @94mph (1.95 60' on racemasters)

 

FYI I run the sportsman II heads and I like 'em.

Just a recommendation..
Good luck!

-- Joe

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/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
1989 Formula 350 4-bolt mains, Forged .030 TRW pistons, SLP 51010 Roller Cam, Comp-cams roller lifters,
Summit 1.5 roller rockers, World Products Sportsman II 2.02/1.60 heads, Edelbrock TPI Intake,
Cloyes Double Roller, timing chain, Mellings oil pump: 13.5 @ 100.23 MPH

Since close of track : Ported SLP runners, Ported Plenum, AFPR, Autometer 100lbs gauge, A/F ratio gauge.

http://www.joesperformance.com

 

Looking at your sig, I see you have an L-98 engine. I assume when you say "swirlie heads" you are working on a different engine? The TBI (L03) engines had the "swirlie" heads.


------------------
If you live in Southeastern US, check us out!
South East Thirdgen

1987 Trans Am 305
14.88 @ 92.81

 

No, unfortunately the previous owner had a Jasper motor installed, they seem to only have one motor for the 5.7 in 91 (ya know one size fits Caprices and Camaros)this one has swirlie heads(187 castings) and the peanut cam...JOY! Made me feel better as to why I was hittin a wall performance wise...just could not get it to pull above 4400 to amount to anything. Hopefully that will change this winter...:-)

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91 Z-28 L-98 G-92 Edelbrock TES, Flowmaster catback(where the cat used to be anyhow!) Accel module and coil, air foil, AFPR, mild porting in plenum Hypertech chip runs 14.40 @94mph (1.95 60' on racemasters)