hello...you sent me email and I havent heard back from you..every thing ok?...Good question-hope you get many responses on this question.... their are 4 different cranks available for the 292- the worst 1 is the forged steel crank only found in 1963-1st yr GM used this crank-they found out VERY quickly how bad this "brittle" crank was for an Inline 6 with a long stroke and a long crank...next they tried ths 6 counter weight cast iron- this was a little better but still not balanced right...next they came up with which some say is the best HP 292 crank- the 12 CW cast iron- see cast iron is fairly soft and actually absorbs more harmonics than steel....this crank has big counter weights compared to the next crank choice-the mexican crank-this mexican is made from Nodular iron (more nickel content for strength)...this nodular crank is the lightest but AGAIN had a brittle factor due to use of Noudular iron....here is some info I have gathered about these cranks-I have heard from many, no matter what crank you use , the 292 harmonics are the worse between 6000-7000 rpm-ESPECIALLY if you use steel rods....all this brings up what balancer are you going to use?-more and more are finding the lighter the balancer on a 292 the better for HP- it works like this-since the crank is sooooo long and has a long stroke, by adding a heavy balancer to the front of the front actually creates MORE harmonic problems-think of it like this- the flywheel or flexplate end is starting to run 1st and if you add weight to the front of the crank , the front of the crank has to "catch up" with the back end-by adding more weight you are creating even more Crank stress and and crank twisting-be very careful here...i do not use a balancer on my 7000+ rpm 292-i have 7.3" large forging rods and I use the heavy cast crank-by having a long rod and Very light piston , you also cut out harmonic problems....mmm sooo, i hope this helps...
what are flow numbers of head you have? are you matching flow #'s to lift of cam?....
Lee
