blk89lx

ok so i got a 306 with kb flat tops and windsor jr heads. springs good up to .600 lift. its got a e303 cam in it now but i want to upgrade to a f303. my question is will i have ptv problems if i install the cam straight up? max lift on the cam is .512 im thinking i would be safe. any advice

mstngsule68

thats a close one. you might be ok, but maybe not....ahh just toss it on there and rotate it and see if it hits

primetime5.0

clay the pistons and find out

mjr46

tossing it on there and rotating it and see if it hits is not acurate nor proper at all cause without hydraulic pressure supplied to the lifters they will collapse under spring pressure loads giving you a false sense of security, a solid lifter must be used when checking ptv or a modified stock one.....as for ptv, lift has nothing to do with it, but based on past experience with the f-cam and in my own car with stock bottom end the f-cam does not create such an issue, but then again I have stock heads so head /valve choice is what'll change the senerio

Joel5.0

Maximum valve lift has nothing to do with PtV clearances + installing the cam "dot-to-dot" doesn't mean it will be installed to the cam specifications....... "dot-to-dot" could be 2°-4° advanced or retarded..... reason why an aftermarket cam should always be degreed and PtV checked with some clay.

DeltaElite121

That's a very radical jump in cams. Not to deviate from your original question, but what's the rest of your setup? Every one of those letter cams shines in it's own way, but obviously you can lose alot as well if you're trying to go too big on an application that can't use the full potential of a bigger jump like that. Just curious as that's the first thing I'm thinking of, and if you haven't bought it yet just remember bigger isn't always better. Sometimes, it's alot worse.

stanguy306

Any reason your going with an F cam? If you are going through the trouble of pulling your cam? I would replace it with something much better a dual pattern cam...maybe Comps XE or custom cam...then its worth swapping? But me personally I wouldnt do the work to go from E ot F...yeah and you should check your PTV. But personal experience I have a stock block F cam and edelbrock heads....using stock pushrod lengths...1.6 rockers.