Looking into a 512 stroker for the wagon. But should I build the short block first, then get the heads and have them done ( eddy rpms ) or have the heads first, then build a short block? I'm asking because I'm confused which would be best to get the compression to about 10.1 would it be harder if I did the heads or short block first? This is an out of pocket build, so as money allows, that's how it will come together, no putting anything on credit.

I would probally buy the heads and put them on the motor I have now and then build the new stroker short block based on the heads I did that on my current motor, took the ported 906 off and put a set of CNC ported Eddy RPM on and picked up .2 ET and 4 MPH with the exact same compression ratio on pump gas I increased the stroke the next winter, .050, to increase the compression ratio from 9.25 to 1 to 10.29 to 1,increased the C.I. from 512 to 518, pickup another .15 and 2 MPH 512 rock Big C.I. motors need big heads, camshafts and exhaust systems

I think either way works. I like the idea of the shortblock first. The big wagon can use the extra torque. Plus you will have time to consider which heads you want to put on top. At 512 inches you are in a motor size that will work well with heads as big as 440-1s and still build some mid range torque.
If you chose to build the shortblock first, be sure and get valve reliefs put in the pistons for as big a valve (2.25?) and as much cam as you ever will run. A 440-1 head top end will build about as much hp with a bowl port than an Eddy head motor will with CNC porting, plus you can port them down the road and really pick up the pace!

How fast do you want to go? Figure the weight and how much HP it is going to take to get there.Then what head can get you there. Not alot of choices so your better off buying the best head you can and then build the shortblock around the head as you then dont have to keep thinking I should of went with a better head after the build.

I always build the bottom end first... then put better
heads on it when the money says I can.. reason why I
do it this way is I can always put the heads on while
the engine is still in the car... and if you can drive
the car with the smaller heads you can work out bugs

Build the biggest short block you can and then worry about the heads, Its easier to replace the heads than pull the motor to build the short block...