I believe some guys use a Buick piston from the later V-6 or V-8 engines.If you stroking the crank less than 1/8 inch you probably use the stock rods and hopefully the piston pin bore can be relocated higher up the same amount.The major limitation on any 235/261 engine is the restricted breathing of the stock head even when fully modified by porting.The only real way to find out is to do the work and see what the result is.Back around 1970 I was drag racing a 650 Triumph cycle in a class that was becoming dominated by better breathing ,higher reving, but much heavier Japenese 4 cylinder cycles.My only option to remain competitive was more power through higher RPM.I was told the absolute limit of mechanical reliability was 7800 rpm.The last season the bike was raced ,the engine was nearing 9000 rpm,Broke vavle springs and pulled the cylinder studs out of the crankcase but never broke a crank or rods.Alex, do it and tell us the results, might be interesting.
