I just bought a 370 stroker sbc that I just wanted the heads and valve train off of it for my 406 and when I pulled the heads off this relatively fresh moter the cylinder walls had no cross hatch finish left  on the thrust side of the cylinder wall, I was under the impression that the 6" rods were suposed to help alleviate this condition!

Lengthening the connecting rods .300" sure isn't very much in the sense of rod angularity. Maybe a degree or two, nothing very significant and that is the reason why the power gain is pretty insignificant as well. I guess I don't have a solution for your problem but I suspect a fueling or lubrication problem.

not sure what a 370 stroker SBC is made from, but I suspect that increasing the stroke negated the "longer" rods.  Also, depending on the ring material that could really aggravate things.  Cheapo cast iron rings eat cylinder walls for snacks.  A nice light tension, thin moly ring on the other hand is pretty gentle.

Steve

do you mean a 377?(de-stroked 400 with a 350 crank)

 It's a .060 over 350 sbc with a 3.625 Callies crank.  

A 377 is a stock bore 350 with a 400 crank (3.75" stroke).  Just for reference a 383 is a .030 over 350 with a 400 crank.  A destroked 400 with a 350 crank (3.48" stroke) would be a 372.    I'm not sure what a 370 stroker is but given the various parts available for SBC I'm sure it's possible.  

sorry arca guy i guess i was mis informed thanks a lot for setting me straight i wasnt trying to sound smug i was in a rush and couldnt finish

This engine was built about 8 years ago and I believe that this crank was intended for an oval track class cubic in restriction moter.  

hmm,

Did that class have claimer rules?  If so maybe it got built with cast iron rings, which are cheap.  Can you talk to the builder?

Steve

This moter was intented for street & strip on NOS but never even seen a hit the only thing he did was run around town w/ it and not to mention he only drove it for 1000 miles. I guess I'll just bring it to my machinist and see what he comes up with maybe just a hone job will bring it back.  

Sorry I misunderstood the circle track comment.  I can't imagine anything other than poor machine work that could take the hone marks out of a cylinder bore in less than 1000 miles.  You know, poor machine work like not putting a fresh hone on a used block when putting in new rings. 

Steve

But as per the topic title, the connecting rod length is far from the cause of the problem. If this engine has a 1.655:1 R/S ratio then it is even higher than a stock 350 (1.63:1) and we all know how dependable a 350 is. If the engine was intended for racing and ended up being "putzed" around on the street I really see a overly-rich condition being the problem.

No problem dude for the misunderstanding I'll take any good input. I just can't understand why this machine shop that he had do the work didn't follow through on a couple of other things on the machine work end of things like decking the block this guy would pop a head gasket everytime he spun it to 7500rpms and the moter was easily capable of every bit of it.  

No smugness taken.  I just had some time to play with an calculator and some numbers.  

preciate it