I was looking at www.strokermotor.com (http://www.strokermotor.com) and saw under the 350 block that there is the stock stroke of 3.48 to give 350 cid, then 3.75 to give 383, then I see 3.875 for a 395 cid and a stroke of 4.0 to give 408 cid. I was wondering, with all these combos, why I have hardly ever heard of the higher displacements than a 383. Why is 383 so common? Is it the most reliable way to stroke a 350? The cheapest? Or with other strokes is there hardly an exponential HP increase to really bother with anything else than a 383? Thanks for answering my questions.

Its real difficult ro clearance the 350 block for anything more than a 3.75 stroke...3.80-3.85 can be done..small base circle cam and a lot of grinding..also..the longer the stroke the more side loading of the piston.

Plus, Chevy made the 3.75" crank for the 400 so they have been readily available, although getting harder to find these days. The other strokes are all aftermarket and much more expensive.

Cam clearance is another big reason IMO. My 383 clears my standard base circle cam by only about .060". Add only another .030 of crank throw and your into the danger zone.

The longer stroke combos work nicely with aftermarket 400 blocks that have raised cam locations (use a BBC timing chain set) and tall decks. The tall decks allow the use of a longer connecting rod, which keeps the rod/stroke ratio in the OK range.

The larger 400 bore also helps reduce valve shrouding so the engine can use better flowing heads with larger valves. This helps feed those extra-long stroke, larger volume cylinders ;)

Also the 400 blocks had a bad reputation for cracking, I remember back in the early eighties many people wounldn't consider building a 400 because word was out the blocks were prone to cracks. The 350 blocks were supposedly stronger so the 3.75 stroke crank was installed. Why they had a rep for cracking I don't know but now everyone is looking for one. graemlins/beers.gif

Bob makes a good point. Everybody is looking for a 400 now because most people have realized that the issues with 400 blocks aren't nearly as bad as the rumor says. Doesn't mean all the 400's are good, though.

i think most of the rumors had to do with the overheating problems. a marginal radiator/fan setup is ok for about any 350, but with a 400 you need to pay a little more attention as to how your cooling system is working. sometimes stock 2 core rads aren't good enough when you have a stock 4 blade non-clutch fan.