I have a stock 89 L98 350 that I want to rebuild.
I have the factory TH700R4 tranny and stock rear-end.

What I would like to do is upgrade the cam, heads, and manifold.

Currently, I am looking at a ZZ-4 cam. However, I noticed someone mentioned (in searches) that you lose some low-end torque. Is this true? If so, will it make a noticeable difference? I would like to keep as much low end & mid range torque as possible.

Also, I am trying to find a set of quality heads to put on that will work well with the ZZ-4 and provide more power.
However, I am unsure which ones to buy. I know Edelbrock makes an aluminum set for $1000+. Would these be alot better than stock? If not, what would you recommend?

I know this topic has been over-used, but I did search and can't find straight-forward answers.
Any advice would be very appreciated.
Thank you!

 

i called TPIS a few weeks ago to ask them the same question. the make a "big mouth" heads cam and intake kit. they told me the best heads for a tpi car are afr's. they have 2 cams for that kit, the zz4 which is a 380 hp kit and zz409 which is 430hp. the price tag for everything is around $3800.

 

i called TPIS a few weeks ago to ask them the same question. they make a "big mouth" heads cam and intake kit. they told me the best heads for a tpi car are afr's. they have 2 cams for that kit, the zz4 which is a 380 hp kit and zz409 which is 430hp. the price tag for everything is around $3800.

 

For the money I like the Trickflow heads. The ZZ4 cam is fine for TPI. I have the ZZ9 cam with 1.6RR and did not loose any torque. In fact I burn the tires worse than ever. You will want a quality set of headers such as Hedman or SLP. You will also want to upgrade the rest of the exhaust system while you are at it. Mandrel bent of course.

If you still have money then the next item is the intake system. You will need a cold air intake system. A friend just compared the stock intake on his 1990 TransAm versus his custom cold air intake. He picked up 16 horsepower on the dyno. He has a 52MM throttle body, ported plenum, and modified SLP runners. Has the Vortec intake. Allen

 

I put down 356rwtq w/ the ZZ4 cam on a stock tune. That works out to over 400 at the crank. How much do you want? Oh, and on a 100 shot it put down 551rwtq which is above 630 foot pounds. So the cam has a lot of tq. Trust me, you'll be fine. And as stated about, the zz9 is a good cam, but I can't stand the a$$ raping you get when you buy anything from TPIS. So I don't.

 

I was hoping to get 300rwhp... I don't know how realistic that is?

I was planning on zz-4 cam, nice heads, headers, TPIS bigmouth manifold, AS&M LTR, 52mm throttle body.

Can anyone estimate how much hp/tq that will provide?

1989GTATransAm, can u give me a part number for the Trick Flow heads you recommend?

Thanks to everyone for their replies!

 

anyone?

 

Hi

I don't have the part numbers in front of me but you can go to www.summitracing.com and find them. I got the double springs, centerbolt valve cover and non CNC'd. If I was to do it over I would get the CNC version for every posible horsepower. Allen