I have a an LO5 long block that is stock with only 30k on it and I put in a re-ring kit so its basically new. My question is: Comp recommends their behive springs when using the 280XFI cam and I was wondering if the behive springs would fit the stock heads without any machining. If it does require machining; then is their a dual spring (cheaper) that would do the job since it will need machining anyway?

I'm Kinda limited to $400-$600 for the valvetrain (since the rest of the engine only costed $75) and really like the idea of the XFI series cam.

What kind of numbers will that combo make? I'm going carbed for now then Modified TPI and aftermarket heads as funds permit.

 

the beehives will fit the stock spring pockets. It'd be about the same price as paying to machine the heads, and buying bigger but cheaper springs.


That's a pretty big cam, it'll run really bad with LO5 heads I think. Once you use aftermarket heads it should really pick up. I'd leave it carbed, rather than TPI in the future.
Converter and rear gearing are optimized for that cam?

 

That cam will not be too bad on essentially stock L05 Swirl Ports.

HOWEVER, the cam below is a much wiser and potentially better camshaft. Less lift, less duration, more vacuum, easier to tune, but it will still pull well to over 5,000 RPM. Peak HP in my old 305 was at about 6,300 rpm with this cam and the heavily ported 081 TPI heads. Amazingly, peak torque was at 3,350 RPM.

CraneCams

I ran this cam in an otherwise internally stock L05 (in my brothers 1995 2wd Tahoe), Keep in mind this was a fresh GM Crate 350 TBI that was cammed from the begining, has a Holley Projection intake, 454 TBI assembly, 454 injectors, L69 Dual Snorkel w/ Cold Air Induction, AFPR, TBI Spacer, High Flow cat, Flowmaster 70 Series Big Block muffler, Cat-Back duals, and that Crane Cam. The stock GM 193 heads were cut for valve lift ONLY and milled for flatness. The block was decked and blueprinted. The stock rotating assembly was balanced. Probably most important is that the Chip is darn near perfect. It also has a fresh 4L60E with a 2,800 Stall in it. This truck flat gets it.

I had to cut down the guides and use LT4 springs/retainers for the lift. When it was said, done, and tuned it pulled 314 FWHP @ 5,300 and 378 ft/lbs @ 3,400. At 1,800 RPM it was already pulling 330 ft/lbs of torque and at 6,100 it was still making 290 HP.

FWIW, this is what the XFI 280 sounds like in a 305.

YouTube - 400 FWHP TBI 312