SalikDDD

anyone know ratio i should go with on these GT40p's on my 289? 1.6 or 1.7? i also want to keep to pedestal mount unless i can get away with stud mounted for less or comparable as i got these heads with no 'studs' or rockers, i'm going to be running a comp 268 cam with a .456 lift and wanted to get the right ones. also are the 'studs' 5/16 or what?

SalikDDD

also should i go ahead and stick in a new set of pushrods? and if so what length? the stock 6.812? or?

67mustang302

Just use whatever ratio the cam/springs are for. And pushrod length will need to be checked.

SalikDDD

alright well, i'd like to go with 1.7 to increase lift to .485 but i can't tell on summit if these crane rockers come with the bolts to hold em down or not since i don't have these :|

67mustang302

The pedestal rocker kits usually come with the capscrews for them. If you go with 1.7's make sure your spring pressure will hold the extra lift.

SalikDDD

well that's what the heads look like now, so i just need to know exactly what i need to have them 'complete' :| i know i sound dumb but well, wait.. i am dumb

my77stang

if you buy the crane 1.7 pedestal style roller rockers you can just bolt them right on. if you want "regular" roller rockers (in any ratio) you can buy a stud conversion kit that screws into the 5/16 holes in your heads and gives you a 3/8 stud sticking up.

the crane 1.7 pedestal style rockers are the same ones ford used on the cobra motors - they are good quality.

also, you can get away with using stock springs BUT your pushing things pretty close. money permitting i would upgrade to something that gets rid of those stupid exhaust rotators and adds a few pounds of seat pressure.