HELP new rebuild with TFS street kit and sealed power pistons

[dave's red89lx]

Howdy all, I was wondering if anyone could help. I have an 89 mustang with the 5.0. I decided to rebuild the motor before putting the trick flow kit on. Had the bores punched .030 over and had new pistons pressed on the stock rods. The pistons that the machine shop got me were sealed power 273AP's. Has anyone used these pistons with the Trick Flow kit? The reason I ask, I started checking the valve clearence and I think the valve is hitting the top of the piston. What I did was torque the head to 30 ft. lbs, Install the #1 intake and exhaust lifters, pushrods, and rockers. Set the lash on the rockers (spin pushrod while tightening the rocker till no free movement, then tighten an additional 1/2 turn), then I started spinning the motor by hand. As soon as I felt some binding I stopped and removed the head. I do not see any marks on the head or the top of the pistion though.
Any thoughts would be great and thanks in advance

Dave...

 

[Black1987Stang]

check it with clay.....put it on top of the piston and do what u just did and if its hitting youll see it in the clay

 

[dave's red89lx]

Oh No!!!!!

Yep the valve is hitting the top of the piston. What are my options?

 

[wild86stang]

What cam and rockers are in there? The Trick Flow stage 1 and the 1.6 rockers? I don't know what those pistons are like, but I'm assuming they have a dome because I'm running the stage 1 and 1.7's on flat-tops with no problem. Maybe you could try a smaller cam or thicker head gaskets. Good luck with whatever you do.