I have a p75 head that was ported and polished by JG engine dynamics with oversized 31.5 millimeter intake valve and 28 .5 exhaust valves. So my question is I'm going to have to replace the valve guides on this head and might have to replace the valve seat. So if I have to replace the valve seats can I replace the valve seats with the valve seats of a p8r b20 head that uses 33mm intake valves on my p75 head? Also will this affect the port flow in a bad way if i was to change the valve size? Engine is going to be a 82mm 13:1 comp with my full built ported ls head with forged pistons and rods running on e85 with crower 405 cams.