Lunati Cams

[shiftpro]

If you're going to port, do it before the valve seat get done. You can smooth out the combustion chamber and if you install bigger valves you will need do some un-shrouding anyway. Leave the exhaust ports rough other than any casting edges that stick out too much. You can polish the exhaust ports all you want. Won't help performance but it will certainly stay carbon clean for much longer. Polished intake ports don't do anything under 7000 rpm. They would actually hurt low speed response. Air molecules actually stick to smooth surfaces. Think 'golf ball'.
And with decking the block (all bbc engine need this) you will need to grind reliefs (intake side) at the edge of the bore for valve clearance (actually it's just more unshrouding). I like to assemble the block after align honing, just front and rear bearings, one rod and piston in #1 and the same in #8. Then with a dial gauge or straight edge and feeler gauge you can measure up how far down the hole the piston at TDC is. I like seeing the piston quench bench (not the
hump in high compression slugs) just under or level with the block. Some blocks need as much a .060 removed to get this. Lots left on the table when TDC leaves the piston 1/8" shy of the deck. By measure #1 and #8 you can verify the crank is in alignment with the deck. If it's not, it's corrected by the decking, not the align hone job.

 

[metal tech]

https://www.claysmithcams.com/hr-88...chool-oem-049-781-heads-to-a-max-of-5700-rpm/

This cam has been used by numerous people in 489 & 496 BBC's with the 049 or 781 heads, rumor has it that Chris Straub designed the profile. If you want to cut thru the typical cam company fog of getting differing opinions depending on the day of the call, call Chris Straub or Mike Jones.