With flat top 2 valve relief pistons (+5cc), on a 383, .030 block, standard head gasket, 64cc aluminum heads, whats the safest lift cam I can run without risking valve/piston interference? Basically, after a lot of reading and questions ive narrowed it down to the Eagle balance/forged 383 bottom end, and the holley systemax engine kit. (aluminum heads, dual plane intake, decent lunati cam), the advertised lift with 1.5 ratio rockers in summit is 490/490, and jegs is 488/510, not sure why they are different but anyway, that cam seems a little small for my motor so is it safe to run 1.6 rockers? about where would that put my lift? I know, a lot of questions... any help is appreciated

Thanks
Kevin

 

You can run huge amounts of cam before valve to piston clearance is encountered. Use putty and double check before firing up the motor.
I'm talking like .650"+ lift.
What exact cam is that?
Yea, might be a bit small.

 

since max valve lift usually doesn't occur when the piston is at TDC your valve timing comes into play as well as the hard numbers. however it doesn't really become much of an issue untill you get into the .600 plus lift range and .65 is more likely a ghood number to start to worry about it.

 

Awesome, that gets rid of that worry in the back of my mind. Now I like the systemax kit but still thiinking its a little to small of a cam, 490/490 so what if i went with 1.6 rockers? Or would i be better looking into something else?

 

Got a link to the whole package? Or feel like listing off detailed specs for it all?
How about the cam specs in particular, lift is just a tiny slice of info on it.

 

Holley SysteMAX II Street Engine Systems for Small Chevy: HLY-300-503-1 - summitracing.com

235/240 duration at .050 490/490 lift and 112 duration

 

I'm runnining identical pistons, 383, eagle kit and 64 cc heads. My cam is 560* lift with 1.6 RR's Your 490 is nothign to be concerned with even if going with 1.6's

 

Awesome, so valve clearance is definitely not an issue...i guess im gonna have to do a lot more research and piece together a top end, none of the packages seem to suit me....any suggestions?