what did ya engine builder recomend?!

or you build it??

and if it was only rebuilt 600 miles ago you should still be useing minrel oil!

ment to run them in for 1000 miles then swap to syn oil and oil filter!

and ford put 5/30w in them from the start so if ya engine like brand new! 5/30 should be fine!

but if ya worried got with a 10/40! but i would say speak to a few tuners on here!

stu,karl(if ya ever see him) paul hills,chrstian and beccy of apt!