so im trying to get some different peoples take on replacing guides. Now keep in mind that what ever head i go with its going to see over 700whp, i got an ITR head and the guides are bad, i have one owner of a shop telling me not to replace guides because with that much power its not advised, then a worker at a different shop says its not a big deal to replace guides at all, now i trust the first guy over the second, So who advises going with a new head thats in good shape or keeping the same head and replacing the guides, i just spent 650 on all new high performance internals and about 625 on the machine work, but the parts and work have not been done yet, so its either dump more money into the head or buy a new head.

 

If the guides are bad replace them. It's not a hard job with aluminum heads. If your upgrading to SS valves you would probably be better off using bronzed guides anyway. If your sticking to OEM/steel valves then stick with OEM guides.

Looking forward to seeing a $650 bottom end take 700Whp. Good luck