Tims 88GT

Hey guys I just bought a set of 165 afr's. They have the 1.90intake and 1.60 exhaust valves. My question is with a stock short block will I have pistons to valve issues? My cam is .522 lift intake and exhaust duration at .50 is 215intak and 224 ehaust. Lobe sept is 112/108. Thanks guys.

90mustang5.8

you may have to upgrade your springs....i think the afr 165's have a max of .500 lift

Joel5.0

You shouldn't have a problem BUT, should always check. AFR 165 springs have a .550" max lift spec, but make sure the springs rate (325#) support that cam.

grabbem88

the springs if you have a "newer" set of afr's will be ok with .550 lifts....but the springs are still not "matched" to your cam...now if you got some pre 2002 heads they will float bad at .530 lift...stock pistons and 190's with your .522 will clear

Tims 88GT

They are brand new heads. Just bought them yesterday. All cnc ported and everything. The springs are good for .550 lift. What do you mean by the springs not being matched for my cam? They have to be better than stock valve springs.

Joel5.0

Lift "support" is not the only item to check on the springs when matching them to the cam specs. You can have a set of springs that would be good for .600" lift, but only have 285# of pressure, valve open.....if the cam requires a set with 385# @.600" lift.......those valves will float if you use the first set.

grabbem88

that's what i was getting at..spring pressure.....the cam you are using will be fine with the springs...seat pressure should be checked either way..

with all the money u have invested...i 'd research for a better cam that will utilize that power u have

5.0stanger

You still have the fox Tim....is it still got a charger? What about the cobra? Been a long time...

ZachW04Stang

Tim whats going on. I checked my piston to valve clearance with clay. I had almost .120 clearance on both intake and exhaust which is more then enough. It only takes about 1hr to check since you only have to put one head on and setup 2 rockers. Your probably fine but with that close lobe sep on the exhaust side you might have the exhaust valve come a little close when the exhaust valve is closing.

Are you still living in manchester? I've been up there a lot lately going down 30, haven't seen you out in your fox.

Tims 88GT

cobra is gone, sold the blower to a friend. got a 2004 ford lightning. and put the fox togeater last wensday and had a headgasket problem so i bought some heads.