89 5.0 heads and stuff

[Old Man]

Any have any experience with the latest cams and heads using the GT40 intake stuff?

The 89 LX coupe I bought last week has a GT40 intake system, bigger throttle body, full length headers, Flowmasters, and 4.10 gear. It has a good clutch but no other mods I know of.

I want to have a car that can hold its own with any factory car like a new Vette but that I can still drive around on occasion.

Anyone been through the exercises? I could put a blower on it, or change the heads and cam. I want to be able to street it.

I was thinking of two ways to go...either TFS heads and a X303 cam or the latest aluminum GT40 heads, stock cam, and a blower. I could ditch the 4.10 gear if I went blower, and go to a 3.55 or higher gear.

One thing that bothers me about the blower is the T5 tranny. It will handle RPM more than torque, although I am not planning on anything but street tires!

The plus of the cam is I like the sound of a lot of valve overlap.

Anyone have any idea if the TFS heads and X303 cam will do it for me? Or if a blower and smaller heads are in my future? I'd like to keep the GT40 intake stuff and the hedders I have because they are all fancy powder coated show car looking stuff.

What kind of problems am I looking at?

Thanks!
Tom

[USMC302]

Biggest problem.....hooking with street tires when you get a blower, lol. IMO I would go with the TF heads and X303 cam you mentioned, you will be ok with piston to valve clearance with that setup, but that is the max I would push without valve reliefs on teh pistons for those type of heads. The transmission will be fine as long as the street tires are spinning, once you start hooking hard with the right suspension, then you will start throwing trannies. I actually ran my stock T5 at 11.20's @ 125 and it's still a good tranny, no problems at all, I just pulled it because I'm going with a racing auto. You can still run the Trickflow heads and cam with a blower and be very streetable, but as you mentioned, you might want to step down on the gears with that setup. Good luck.

[Old Man]

Originally Posted by USMC302

Biggest problem.....hooking with street tires when you get a blower, lol. IMO I would go with the TF heads and X303 cam you mentioned, you will be ok with piston to valve clearance with that setup, but that is the max I would push without valve reliefs on teh pistons for those type of heads. The transmission will be fine as long as the street tires are spinning, once you start hooking hard with the right suspension, then you will start throwing trannies. I actually ran my stock T5 at 11.20's @ 125 and it's still a good tranny, no problems at all, I just pulled it because I'm going with a racing auto. You can still run the Trickflow heads and cam with a blower and be very streetable, but as you mentioned, you might want to step down on the gears with that setup. Good luck.

Thanks!

I've decided to change the intake system to TFS along with the heads and all. They claimed about 25 more HP with the TFS intake to go with the heads instead of the GT40 stuff on the car now. They said the combo would put the 302 solidly at about 400 crankshaft horsepower without a blower, which is about all the stock block and bottom end will handle.

That would also be a better match for the 4.10 gear in the car now.

I went through the driveline stuff on an 83 I had. I put a 351W with ported aluminum heads, single plane intake, and a big mechanical roller cam in it. I could run low 11's off the motor alone and mid-10's with a little NOx but neither the 8.8 28 spline rear end nor the trans would hold with slicks on the car. Once I start I can't stop, and I sank a fortune in that car and eventually put it where I can't drive it except at the track.

This is a very clean car and I don't want to start changing every part in it. I need to control myself this time. :-)

Tom

[USMC302]

Sounds like you made a good choice, I favor the Trickflow components as well. Trickflow also has a camshaft that will work well with those heads. Unfortunately I disagree with the 400hp at the flywheel estimate, it may be a little lower than that. I was running right around 400 with my 331, with my h/i/c combo on stock compression. If you plan on running a lot more compression, I think you will be closer, either way sounds like you've had plenty of power under your seat before and will enjoy this one as well. Good luck trying to control the urge...haven't met many that could.