Tang

I am posting this for my dad. He has a 91 RS with a 305 TBI. He got a 1991 Caprice police package engine for free. He wants to know what he should put in for the heads and intake. He also wants to know the cam specs for the z28 of 1991. He is keeping the bottem end stock and this is a daily driver he just wants more power, so nothing too ratical he still wants to use regular gas if possible. Oh ya he wants to know what PROM to use when installs this engine. Thanks

angel71rs

Vortec heads are by far the best bang for the buck. Tests show about 40-50 hp increase from just the heads. Buying a pair of complete vortecs will probably be cheaper than rebuilding stock heads. Only hitch with these heads is that they require an intake with a matching bolt pattern, but since he's looking to buy an intake anyway, it's not that big a deal. An Edelbrock dual plane, like the Performer rpm, or so would be good.

BryGuy1

The stock 1991 350 TPI lobe lift is: I=0.275 E=0.285 @1.5 I=0.412 E=0.427

If he has the 1991 police package including the computer, convert over to the TPI setup. Extrude Hone or port the plenum, intake runners and base. gasket match the head. I am unsure myself about a slight mod head with a cost/performance factor. The cam could be a notch bigger for the "daily driver" fun car!

Yellowknifer

For Daily driving I'd have to give the nod to the Vortecs. You can make those L98's breath though if you have experience porting heads. Then you could go with the TPI setup (which looks sick ) and port the heck out of that too . Siameseing the baseplate can yield pretty nice gains. Probably would want to go with an edelbrock base.

pcolaIROC

vortecs are great heads but you should not port them, there is not a lot of room to do so, so you would be wasting your money. if he does go TPI, he would need to get the vortec base from Scoggin Dickey, they are the only people that have it and it was designed specifically for the vortec heads. you WILL need to get bigger runners or port the stock runners, the are a big choker on tpi engines. a bigger throttle body, like a 52mm, wouldn't hurt. neither would a 100 shot of nitrous

------------------
red 89 IROC 5.7L A4
-K&N air filter, Flowmaster 3" exhaust, Hedman shorty headers and 3" Y-pipe, MAC offroad pipe, Vortec heads, B&M Transgo shift kit

"THINK OUTSIDE THE BOX"

Tang

Thanks for the info guys. My dad has decided to stay with TBI instead of TPI. He said he'll go with the vortec heads and intake, and either buy a new "cop" car cam or the cam for the Z28.

He still wants to know if he has to get different prom to run the eninge correctly? thanks

RedIrocZ-28

Well... I wouldn't think he would need a different prom to run the car correctly, no. The cam is soooooo mild that it should be ok. In all honesty, he should go with a bigger cam. If you are doing heads and intake, throwing such a small cam in there will yield small gains. If anything I would recommend a cam with lift numbers around .460 or so on the intake and exhaust sides with a duration of no more than 215 degrees on either the intake or exhaust side. That cam right there with the Vortec heads and Edelbrock base would yield an honest 40 RWHP or so. The best part is it should be all computer compatible. Although, a PROM burned specifically for the car would yield much better results in terms of gas mileage and performance any day.

Tang

Alright I'll tell him he should get a bigger cam and that it would be ok to use the stock prom, but if he wants better mileage and performance get one custom made.

Where could we get one burned? How much? Thanks