I have Patriot Stage 3 Heads and Comp XE270AH's. I should be good to go, as far as PTV goes right? Provided installed and degreed properly.

 

I would definitely check it. If you are still running the 98 short block you could run into troubles. It's always worth checking.

 

I will definitley check it. Anybody know for sure or not?

 

I am running a stock 98 shortblock.

 

You are going to get PTV contact. You will have to get pistons with valve reliefs in them. Comp cams come with like 10* advance in them which is fine for PI heads and 99-04 shortblock but not PI heads and 96-98 shortblock. That cam is to big go a bit smaller.

 

I went through this with my car. Some say it will work some say no. They are both true. I sat on hold for 20 min with comp cam and there answer was:" Ford had two different manufactures at the time making the motors. It depends on what piston is in your motor on has a bigger lip around the outside making the valve hit and one does not." When asked how you can tell what piston you have they said "pull it out of the cylinder". So in turn instead if paying for the install and not working i just went with the XE262. If you have a stock block they are better anyway cause there power band is a lot lower RPM's. The XE270 power band goes all the way up to 6800 which i would not suggest taking your stock short block up to.

 

....has nothing to do with what head is on what block but all about installer error.


You won't have PTV if the cams are degreed in and adjusted properly. Comp grinds in 4 degrees of advance and that combined with the poor tolerances of the stock timing can give you up to 7-8 degrees advance on 1 or both banks. There is plenty of clearance with the valves and piston rim if they are installed correctly. Those who get PTV are those who just install them straight up with the timing marks and don't check to see where the stock timing gears are at. The stock timing can be off as much as 5 degrees in either direction so there is power to be gained also with deegreeing them.

 

Thanks alot guys. I'm just going to go with this, and take my time doing it. So 270's are going on the stock block.