In the process of rebuilding my 351, I swapped from E6SE heads to E7s because of a bad valve seat. I do know that since they are both production heads I shouldn't need new pushrods... But, what if I wanted to close my quench distance? And went from a .047 gasket to a .040 is there normally enough room to do this in a ford or do I need a pushrod length checker?

 

I think it would be worth the $15 for the checker for piece of mind that your valve train geometry is good. Proper length will ensure the right pre-load on the lifters, the right toque on rocker bolts and wear pattern on your valve stems.

Depending on your valve clearance you could go even thinner than .040, but before you buy anything I would suggest checking your piston height in relation to the block.

 

I had it all written down at one point but can't find the paperwork go figure. But it was a found to be a generic rebuild and if I remember correctly, the pistons are "pretty far" in the hole. That's why I was asking. The original plan was to be done with this swap a year ago but well life happens so now I'm trying to get it finished.
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Yeah I hear ya, funny how these project can snowball and get pushed back...

What I did for my build, and I hope someone could confirm if this is right or not, was to take a dial gauge with magnetic base to find TDC, then I took a straight edge and feelers to determine how far in the hole. I was only about .010 +/-, so I went with a .029 gasket. IMO it's worth it as an ideal quench will help reduce detonation and perhaps up the compression a bit.

 

I seem to recall reading on one of the piston maker's sites that ideal quench is about .040", so using the thin gasket it a good idea. You have to be careful with oversize pistons, it used to be common practice for them to be "de-stroked" to end up with about the original compression ratio.


So a +.030" piston would sit .030" lower in the cylinder. A really bad idea, since that actually increases chances of detonation, as well as lowers efficiency and power very slightly.

 

Yes, between .040 and .044 is good. I've gone as tight as .037 on a build with no issues, but that was a clay each piston and measure piston to valve clearance.
​​​​​​​I think the reason I'm over thinking this is because its my first nonadjustable valvetrain build. Even the other fords were upgraded to adjustable rockers so close was a nut turn away from right. This thing is measure for the pushrod and bolt it down...