Ok. I was originally going to go with a Doug Herbert hyd. roller cam but now Herbert Performance is telling me they are having trouble getting late-model billets from the cam grinder so they can't grind the cam I wanted.
Here were the specs: int/ex: 222/234 @.050, .499/.502 lift, 112lsa.

The motor is a 87-up "L98" 350 which was originally TPI but now converted to carb with:

- L31 Vortec heads (with screw-in studs and what-not)
- RPM intake
- 750cfm VS Holley
- 1 5/8" headers, 3" single exhaust
- Stock 700R4 (until she blows), 3.73 posi.
- 100HP shot of nitrous

The thing is that I can't find a hyd roller cam with around the same specs anywhere. I have LT4 valve springs installed on the Vortecs and they can only support .525 lift and the valve guides to retainer clearance is around the same. Sooo this brings me to my question...

What cam should I go with? The last motor these heads were on saw 12.6's with the Edelbrock RPM cam (234/244 @ .050, .488/.510 lift, 112ls) and I'd like a cam with close specs.

I've looked through tons of catalogs and see nothing with that much duration and under .525 lift. Keep in mind this motor sees nitrous and its not a daily driver but is a street car.

Thanks,
Chris

 

This part #270-119831 at www.jegs.com

That's the closest I could find. It's pushin' the edge though. The exhaust lift is .528"

 

Try the Comp XR 270 roller cam. It has intake lift of .495
and exhaust lift of .502.

 

http://cgi.ebay.com/ebaymotors/ws/eB...tem=1863448566

Or try a SLP 51006, that's even closer to what you're looking for. I had one for sell but have since stuck it in my spare engine.

Comp Cams 8-412-8 is also close to what you're looking for.

 

Thanks for all the replies but I'm still in the same boat...

The #270-119831 cam is on back order and has been on backorder for awhile now. I'd actually use it.

The XR 270 doesnt seem to have enough duration and wont be the best with nitrous because of its 110 lobe seperation. Actually it has the same duration as the LT4 Hot cam

The SLP one is designed for computer controlled cars so it has all the drawbacks of your average FI cam.

 

Pull the heads off and fix it.

You need to step up to a better 1.44" spring anyways to run
cams like what you want.

 

Well Herbert Performance just called me and said the cam was shipped to them today and will be at my door sometime next week.

You really don't think I would be alright with the herbert cam and 1.32" LT4 valve springs? The machine shop said I'd be fine. I'd *really* hate to dump more money into these heads but I know its a bad idea to get cheap on things like valve springs...

Thanks,
Chris

 

I'd be inclined to agree with F-bird, too many people have had those springs break on them. But it's your call, being your motor and all. It's kind of like asking somebody "do I have enough life insurance"... only you can answer that, it's your own sense of security. For myself, I would not run any GM springs whatsoever in anything with a cam bigger than a 929; and even with a wimpy thing like that, a motor will run better with some other springs. I know how you feel about those heads though... you start pouring money into them, their attractive fetaure evaporates rather quickly.

 

The Lt4 valve springs are enough to control the Lt4 cam
in a lt4. The cam you want to use has more lift , faster
ramps and is designed to be used at a higher rpm.

These fast action hyd rollers need a better spring than the factory LT4 spring.
Get the heads machined for 1.44 dia springs.
Use a Comp 987 or crane 99838.
If you setup your valvetrain right for your new cam the first time
you'll get the performance you're looking for and avoid the
headache and heart ache if breaking parts (valve float)
and having to re-do it.

Sell the LT4 stuff to someone else with a milder setup.