For a 550-ish HP small block that normally spins to no more than 7000 rpm, is it worth wild to modify the stock 360 block for a 4-bolt main set up??

http://www.milodon.com/main-caps/main-caps.asp

IMO no.

Nice insurance , but not essential I.M.O.

No way man studs & steel 2 bolt caps are the way to go you really don't want 4 bolt on a 360 block, not enough meat in the webs, At that hp the stock caps will work fine

At what horsepower, rpm and compression ratio would you guys have differant opinions???.

I'm kind of having a hard time thinking my 2 bolt main will be sufficient at 8000 rpm , 13.5-1 comp and 600 hp.

I built a max effort w5 stock block 408 a couple of yrs ago with 14.5comp, methanol injection and decent rpms and did the said upgrade with 1 through 4 pro gram billet caps with the center three being the offset angled outer bolts. Block broke in the mains right beside where the outer offset angled bolts were drilled and tapped in the mains after 10 passes. Just not enough meat there in the stock block even though there offset like the block is. I bet to the edge of the bolt to the outer edge of the main web there is like 100thou or less. Some people make it work.... didnt for me. I now have a R block which is what I should have started with. JMOP

We turn 7k with a 360 block stroker 414 cid, callies crank, BME rods & light ross custom pistons, apr studs with pro gram steel caps, it will go to 8k but I wont, @ around 600hp + or - some for 3 seasons, When I finish my race block I will swap out the parts

I would buy the billet caps in 2 bolt or if you cant find them buy the 4 bolts and just run the standard 2 bolts.

Good info thanks.

Thank you guys...