Glenn, would the same piston mods work if I were to stuff the 4.2 crank into a
3.5 block( ie, on a 3.5 piston?)? And, as I don't know formulas all that well
what kind of displacement would we be looking at?
Thanks for all the informed replies!
Tom
88 RR
Glenn Towery wrote:
> Tom & Dave The G.M. 215, Rover 3500, 3900, are the same stroak. The 4200
> is .200 more (3" stroak). What we do to moke a 42 run is take a 3900
> piston & cut .090 off the top of the piston & .125 off the bottom
> skirt, with the low comp. 3900 rover piston you have 10 to 1 comp. with
> the 9.35 rover piston, we will C.C. out in 2 weeks, but I am sure it
> will be 11 1/5 to 1 (I hope I hope) There is a cast piston that you can
> use, that you open up the wrist pin hole to .927 from .875 & you have 10
> to 1. I have a 4200 in my M.G. & it is a LOT of fun comp. to a strong
> 3500. 74 1/5 G.T.,3500, 416,000
> miles 74 G.T.
> 4200, 123,000 miles in 3 1/2
> years 72 B 4900, & borg
> warner 6 spd. 15,000 miles A
> good ride is not what states you cross, but what time zones you
> cross!!!!!!!! Glenn Towery
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