R65 heads vs /5 heads

[Lurker_no_R65]

I got a very good set of R65 rockerarms from Rob (thx, Rob) to convert my /5 heads to early /6 needle bearings. There are so many variation of length and designs for the rockerarms on R45/65 and /6/7/etc out there, that trial and error seems the only way to go. I am doing a couple of measurements in the next couple of days but would like to also ask the question here where the R65 experts are. Does anybody know if the vertical distance between cylinder studs is the same for all 247 and 248 airheads (call it rocker block pitch if you like!)? I studied Anton Largiader's website on rockerarms but he doesn't refer to R65s. I hope I can make the R65 rockerarms work (EPC says they were used on /6s) and am looking for input to that effect, any input!

Cheers, Stephen

[Barry]

Don't know for sure Stephen but my guess would be they are the same. If a definitive answer is not forth coming I'd be more than happy to whip a cover off and measure mine for you.

[nhmaf]

I'm not sure - I've thought this was the case but could be wrong.  I presently have the rocker covers off my 1978 R100/7 and can take some measurements and post them here - got too many irons in the fire at the moment to take my R65 covers off..

[bruce_launceston]

The R65 rocker block/head studs are spaced at 93mm x 71mm (centre to centre) measured off my old head gaskets.

[Lurker_no_R65]

I am getting 93mm and 72mm on a /5 cylinder, and the same on a R100S. Close enough to assume they are the same size.