PewterC5-2000

All,

I'm looking to replace my LS1 short block due to the fact that my lifters/cam munched on eachother. My question is, why is it that the majority of the built 347 blocks out there have some sort of valve reliefs, i.e. -2cc, -4cc etc? I'm assuming this is due to folks want to add power adders, is this a correct assumption? Any input is appreciated as I'd rather go to the stock flat tops instead of wondering about the affect of this on my H/C daily driver.

TIA,

DONAIMIAN

iTrader: (18)

The only reason for a valve relief is so when running a big cam, you wont have issues withthe valves hitting the pistons.

PewterC5-2000

I understand that but it just surprises me that the plain ole flat tops aren't as commonly available (in built blocks) as I would of expected.

MeentSS02

iTrader: (11)

Most people that are rebuilding an engine are going to be getting the most out of it and will need the valve reliefs... I think I would get valve reliefs "just in case" simply because IF I wanted them later in the future, it would be such a bitch to do it then rather than when the engine is built to begin with. I see what you are saying though...when/if I get a new engine, I probably still wouldn't run a big enough cam to warrant the reliefs. I'm still having fun on my stock cam actually...

slow trap

iTrader: (22)

the reliefs won't drop compression much.for each cc it is only around a tenth of a point.you could either run a set of thinner gaskets or shave your heads some to gain back your compression.