camshaft questions

[94 Cobra 5.0]

ok guys this is the camshaft that im looking at to throw into my cobra. my question is that the lift on the cam says that it is those numbers with stock rockers. but since the rockers on the cobra are 1.7's what will the lift numbers be with the 1.7's and the other question is what would be the max lift cam that you can put in our cars without doing valve springs. thanks in advance.

Small Block Ford: 1985-93 HO 302, 5.0L (with roller tappet cam), 1994-95 351W (with factory roller cam when used with mass air EFI), hydraulic roller camshafts

Advertised duration: 299 intake/309 exhaust
Duration at .050 in. cam lift: 222 intake/232 exhaust
Gross valve lift: .510 in. intake/.534 exhaust
Lobe separation: 112 degrees
Peak horsepower rpm: 6,000
Peak torque rpm: 2,750
Power range 2500-6000 - Fair to slightly rough idle

 

[BlownFiveLiter]

Wow, that's gonna be a lot of lift with 1.7's. The intake will be about .541 and the exhaust about .567. With that much lift, I'm almost certain you'll need valvesprings, but the bigger issue is that you'll probably have a ton of piston to valve clearance issues with that much lift. FRPP says to check clearance for their "F" cam, and it's only .512 lift. Hopefully someone else will chime in with their personal experiences with high-lift cams without problems, but I'd possibly consider stepping down to 1.6 roller rockers that the cam is spec'd for.

 

[95COBRA241]

That's a lot of lift for both the valve springs and the pistons (PTV). If you're going to use that cam I suggest you get a new set of springs. Trick Flow sells a set for stock heads with lift capabilities up to .600. You will definately have to notch the pistons with this cam whether you use 1.6 or 1.7 rockers IMO.