cb750 76/78 motor capatabilities

[dixiedevil]

Ok so i have a 76 cb750 motor w/ everything(in parts), and I have a complete 78 motor that I fixed and had running great. replaced the head, using the 76 head,because i had a problem with a valve, set the timing wrong and blew the rings on the #4. 78 rings are difficult to find and pricey when they are. I really have no money and i can afford to buy CycleX's piston kit($168+ship) but cant afford the $100 to have the sleeves bored. So then im lookin at another site and its gonan run me $120+ship for just the rings.
Im wondering since the head from the 76 motor fit the 78 (jugs) like a glove can i use 76 pistons and 76 jugs on a 78 bottom end? That way when I have to replace the rings again for whatever reason i can get them easily and not for an arm and a leg?


any help will be appreciated.

Charlie

 

[Rocan]

try it... i get the feeling compression will be bumped... or is it lowered?

 

[Wee Todd]

78 super sports used higher compression pistons ,,,,,swap in the older stuff ,,,,ever thought of a paper route

 

[dixiedevil]

talked to Cycle X guys today. sorry for not being specific. 750 K motors im talking about. Turns out i can run the 76 top end(jugs n up) on the 78 bottom end.

i will be clarifying some issues about stroke issues, but they didnt mention anything important. They said i could just throw everything on.

Also i am seriously considering the paper route. But now im lookign at $120 for Cycle X approved piston rings and a complete gasket set.

i will follow up on the rebuild so the info will be out there for others interested.