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TPI/vette head advice. Grumpy? Anyone?


Guest 73TPIZ

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Guys, i'm getting ready to install my 'vette alum heads (cast#10088113) on my '86 305TPI motor. i read that i don't need the pushrod guides, but to use rail type rockers. is this right? can i use my stock length pushrods? Any suggestions on head gaskets? Will 1.6 rockers help my cam (Crane#113932 .440/.454lift 210/216dur@.050 114deg lobe sep) or is there another cam you could suggest. I don't plan on turning it past 5500 rpms.

 

The car runs the quarter 13.167 @ 102 w/ the stock iron heads and ram's horn center dump manifolds and i'm hopeing the alum heads w/ block huggers will put it in the 12's. what do you guys think? Also, besides swapping the 5.0 for a 5.7 and trashing the TPI (heard that already), are there any mods i can do to the top to help it breathe better (siameze,bigger TB,bigger MAF,etc).

 

i'm not a big fan of this engine size but it just means more to me to beat a Mustang 5.0 with a P.O.S Chevy 5.0 at the track (really pisses off the blue oval guys) Sorry such a long post but I really would appreciate any advice. thanks

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That's impressive! My buddies 305 powered '74 'vette convertible ran 13.97 in Baytown with just a cam, headers, and aftermarket intake (the OEM was warped)with TH700 stock converter and 3.08 gears. I think the TPI 305 and T5 are the PERFECT Z motor/trans, especially the 91-92 235hp motor. I think your cam choice is excellent. I would not run 1.6 rockers, personal preference, but I think it more than a little monkeys with geometry (that said I have them on my LT1...). I'm not sure if the L98 heads use self-aligining rockers or not, but it may depend on what year because I don't think the '86 heads did. If it has guide plates, use non-self aligning rockers. The aluminum heads have the pre-87 bolt pattern so if you have an 85-86 TPI 305 you can use your existing intake. If you have an 87 and up 305 you will need an intake. If you have the serpentine setup and have not done underdrive pulleys, that alone might get you in the 12's.

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the cam you pick is an excellet choice if your only spinning the engine to about 5500rpm, your'86 305TPI motor matches the cam perfectly, I used the same cam in a 350 to run low- mid 13s in my vette when I first bought it. 1.6 rockers will help your cam in that engine and matches the TPIs intake and cylinder heads flow curve but I doubt youll gain more that about 5-7 hp.

here these ported runners should give you about 20-25hp once modifyed

 

http://www.slponline.com/view_product.asp?PARTNUMBER=20002

 

I payed $300 for these several years ago so this is a good deal if your still running a TPI, BTW it won,t come close to what changing to a STEATH RAM INTAKE will do for you but heres a few ideas on how to get the most out of yout SLP runners and ported plenun on your TPI

 

siameseing your runners over the upper 1/3 to 1/2 of thier internal length when combined with a ported base does raise the rpm levels your engine will effectively make power in by about 500-700rpm (a worth while gain ) but I would NOT ADVISE SIAMESEING the base as just the upper runners show the gains from my testing

http://www.eecis.udel.edu/~davis/z28/buildup/plenum/

 

http://www.thirdgen.org/newdesign/tech/siameseport.shtml

 

things to read

 

http://www.thirdgen.org/newdesign/faq/thirdgen.shtml

 

http://www.thirdgen.org/newdesign/tech/tpimod1.shtml

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