Engine Question On Heads - Ford Motorsport

You will have to measure, regardless of what heads you use. Are you looking at only a flat top piston? Most come with a cut out, for intake and exhaust valves..Depending on how far the heads have been milled, you MAY need to mill your intake to fit..
Best bet will be to mock them up, and measure everything out..

You can covert your hydraulic lifter to solid so you can get an accurate reading on P-V clearance. Just remove the clip and take the lifter apart, you can stack washers inside lifter to where you have just enough give to the pushrod cup to put the clip back in. I used a 1/8" pipe coupling with a 1/8" pipe plug to adjust height to barely get the clip back in, and whala, solid lifter.

PTV clearance should always be checked - you can buy a single hydro lifter and convert that to solid rather than converting one you plan to use. You can probably convert one to solid and convert it back to hydro and then use it, but I always worry about the little spring clip and whether everything will stay together at speed once I've had it apart and back together a couple times. I would tend to worry more about whether there's enough material left in the heads for a good strong seal to the deck than about PTV clearance. After checking PTV clearance you should probably mock up the intake to make sure the intake won't need to be milled to seal up and match with the ports on the heads. If the heads have been milled a lot you will want to make sure you check the pushrod length and use the correct pushrod length or your adjustable length pushrod when checking PTV clearance.

If they were mine I would also take them to my local machine shop and have them checked for cracks, get them cc'ed, make sure the springs are set up and shimmed correctly so they will work properly with the cam, valve guides are good, valve seats in good condition, etc. It doesn't cost that much and you want everything to be right to make sure the motor will function the way you want. Without knowing the cc volume you don't know what the compression ratio will be and whether it's pump gas friendly, etc.

Has the block been decked? How far in the hole are the pistons? Compressed thickness of the head gaskets you intend to use? These are other things you should know to calculate compression ratio. I recommend you also check dynamic compression.