250 and 350 powervalve differences?

[twinrock]

I know they are different..but by how much..I have a set of 350 cylinders needing new powervalves as one was missing and one damaged..im moving them on to jools however ondering if 250 ones could be ported or made to fit..as I know of lotsmkf 250 cylinders sitting doing nothin..

[gman]

If nothing else there would be a difference in the width of the valve at the cylinder? Exhaust Port width on the 250 is 34.25 mm the 350 43mm.

[twinrock]

Yeah I would asume the 250 would be smaller..but thats a good thing.easier to take metal away then add it on..☺ I can lay my hands on many 250 cylinders just dont have any infront of me..maybe with a couple of hours work they could be reshaped to run in the 350.. just a thought..