VN Heads and manifold conversion Help Please...

[needwork2-4fillhabbit]

Hey all posting this up to prevent further unforeseen expenses. I've got a series one VN V6 motor thats nearly fully rebuild (just waiting for a few more bearings).. I just bought some series 2 ported flowtested and bathed heads that i will fit to the block. I need to know if there is any differences in the two blocks.. (i dont think there is). I also need to know if the series 1 rocker bolts are bigger than the series 2 bolts (not length). I have a set of series one roller rockers that i may need to take the series 2 heads into a engineer to get them to drill and tap the mounts or fill the mounts then drill and tap. It all comes down to how much bigger the bolts are in the series one rockers. Thanks to all who know and post. Almost forgot also have series 2 manifold..

[needwork2-4fillhabbit]

Further searching ive found out that series one are 3/8 and series 2 are 5/16. So 3/8 is nearly 10mm and 5/16 is 8mm so looks like the drill and tap will work unless someone knows more differences?