i was thinking about a t-rex (not going to be much of a daily driver car anyways) but i have a set of GTP stage 2 LS1 heads unmilled BUT with Ferrea 2.02/1.60 valves. am i going to have clearance issues with those valves even with stock size chambers? if so what should i change about the cam to make it work with them? LIFT?DURATION?LSA? i have no idea so any info would kick ***.

 

yes...it'll be too tight regardless.
The different valve diameter and thickness (of the head) will cause things to be too tight.

The duration and LSA are the main factors in PTV clearance

 

any suggestion on how much to alter each to make it work?

 

I would look towards a diffrent cam. The T-rex was designed for max power with stock heads. From the graphs I have seen, it dosen't perform as well with ported heads. Regardless, it won't fit with those valves so you'll have to do something diffrent.

 

hmmm...i might just keep the heads for something different and stay with stock heads for now.

 

if your still wanting a big cam you can look into the x3 114, that should clear. but with a great set of heads you dont need a big cam.

 

this is true JRP...these GTPs are pretty sweet too

 

Not true. Big cams work great with big heads...and the Trex is no exception. It wasnt necessarily designed for stock heads...it was designed to fit with stock heads and not have to notch pistons.

 

Thanks Brad you are correct. I don't know where people get to thinking this cam is not designed to make good power with ported heads. It was designed around stock heads at first for P/V reasons.

 

I'll see if I can give you some ET proof tonight...

My first outing was in 4000+ DA so I don't really want to comment on the times

 

Sorry to hijack, but how do you like driving the car around town? Thunder told me the vacum the cam needs would make the brakes all hard and anything below 2K RPMs would make it buck like a wild horse, i still want a big cam but trying to determine if it would be good to drive it on the street mostly, not daily.

 

brakes aren't alot different...just a bit stiffer when idling around.

the car don't like being under 2K...it will buck.

 

Adding both big heads and big cam would make for a big rpm set-up. I'm not saying it wouldn't make more peak power, but the under curve seems to suffer from the graphs I've seen. If your building a track car, by all means, go ahead, but I think a street car could use a more suitable, smaller cam to keep under curve power up and the rpm's down.

 

the car is street/strip...but is a th400 setup with 3.42 rear gears and a 4,000 stall....i might just stick with the stock heads until i build a motor to work with an even bigger cam. T-REX with stock heads is very impressive as it is.