On a zero deck,flat top piston (with no valve reliefs) 383 with uncut closed chamber iron heads and a .039" head gasket,what would be the largest cam that could be used?..Of course I will properly check piston to valve clearance once installed however I am just looking for a good starting point...Thanks

You're sure it's ZERO deck with NO valve reliefs? If so, you better not go crazy with lift or duration if you want it to fit. I would go with a comp XE268H. Nice cam for a 383 without excessive duration or lift. Should work nicely for you and give a decent lope at idle. Someone posted a vid of their 383 car with that cam a while ago, sounded great.

Thanks for the response...Yes it is zero decked and the forged TRW pistons have no valve reliefs.. That is the cam I was thinking of.

I had a 383 simular to that and I ran the Crower Compu-pro 271HDP 112LSA cam that specs out at 222/234 duration @ 0.050, 0.486"/0.496" lift with 1.5:1 rocker arms. Originally I used the single valve springs, but after accidently over-reving the engine and bending two intake valves I went with the dual valve springs. I should have had the pistons cut for valve reliefs when I was assembling the engine.

One thing you could do is install some valve checking springs on the head, setup a degreeing wheel, install the heads, and measure and record the piston to valve clearance (put a dial indicator on the spring retainer and push the valve down till it touches the piston) at TDC through about 30-degrees after TDC in at least 5-degree increments or smaller.

If you post that infoemation along with the cam specs you plan to use I can plug the info into the Dynomation 5 software and give you an estimate of the valve clearance.

Thanks 451...I am considering 3 cams..XE268H 224/230 477/480 110 LSA...XE274H 230/236 488/491 110 LSA...XE275HL 231/237 525/525 110 LSA

I'm running the xe284 in my street 383...works well but needs convertor. my pistons were .080 down and heads milled .060.516. The p/v was at min. Be careful and check. you can adv the cam if you're close.

It's been years ago (But I still have it...) I built my 383 using the TRW forged flat tops. I originally built it with 906 heads and the MP Hemi Grind cam and that was no problem. However when I swapped the heads for some 516 heads with 2.14/1.88 valves and the MP 509 lift cam the valves were just barely touching the pistons. It was just enough to mark them when we were breaking it in. We wound up taking it apart, flycutting the pistons, and clearancing the top of the cylinder slightly for the exhaust valve. Oh yeah mine arent zero deck either, they're about .015 down in the hole.

Advancing the cam will give less intake valve to piston clearance,but will give a larger exhaust clearance.Retarding the cam will do the opposite,a split in the middle creates the most clearance.

Exactly. And since the exhaust is the one coming off the ramp, its the one thats gonna smack if you're close or over rev it and float it. The only thing to worry about on the intake is if the chain is loose on engine decel.

I'm glad someone asked this question, I have a true 10:1 383, it's never been decked and the flat top pistons come all the way to the top of the bore and I was considering having the pistons cut for valves. Anyone know the cost of having that done or if there is enough meat in the piston to cut them? Sorry if I highjacked ur post but reading it led me to finally ask about it:)

No problem...I think I am going to stay under .500"..Most likely the XE274H cam...Thanks