Jock, are you referring to the bolts that attach the manifolds to the cylinder heads? If so, there's nothing particularly unique about them- - - - -they're simply Grade 5 3/8-16 bolts. (3/8 U.N.C.) If you can find bolts that will allow 1/2" or slightly more thread engagement in the exhaust port threads they will work just fine. Slightly over-length bolts can have the threads trimmed to fit without any disasters, also.
Jerry
Yes Jerry that's the ones. I'd looked at ARPs site and their bolt kits were all equal length,but the centre port bolts obviously have to be longer to compensate for the thicker casting.
Asking hardware stockists here for Imperial stuff nowadays just causes brain farts.
Remember...we've been Metric here for over 40 years.
I was a little unsure how much thread engagement was permissible,so your reckon 1/2" minimum will be sufficient?
Now i've got a better understanding I can get the correct bolts online.
I wish we had McMaster Carr here.
Thank you once again for your valued input.
