max cam lift

ok.. so a friend of mine asked me if i knew the biggest cam you could throw on a gen1 sbc with a stock bottom end.. it does have aftermarket speed pro pistons equivelent to stock.. his hes the roller cam retro fit kit so its full roller.. i honestly not sure.. he has heads to handle it.. but i thought i would ask here and see if anyone knows???

oh and he just threw in a 240/248 .558/.558 cam.. i think he should be fine.. but can anyone back me up?? i dont wanna tell him yes and bend a valve or something

the max lift is determined/limited by what valve springs he has. and obviously the springs he has would depend on what heads he has (or whoever manufactures them). he shouldn't start running into any problems with piston-to-valve slap unless he has higher ratio rockers (i.e. higher than 1.5). you have to find out from the manufacturer (call them) if those springs will handle that kinda of lift. if not, he'll get coil bind and he can plan on replacing quite a few valvetrain parts in the near future (i.e. pushrods, rockers, and springs... maybe other stuff too).

if he did a roller conversion, he'll also want to make sure he gets the correct lenght pushrods for his application... because they'll be much shorter than the factory pushrods.

also, if the heads have been angle milled, there could be clearance problems. but i imagine that he probably hasn't done anything like that.