Machining will not be an issue if needed this season. I have other resources for that. Thanks again for commenting on my post.

Ya I can't even open my golf course until the 13th or later if it gets pushed back. Battle Creek course opened for one day before being shut down. In addition had to pay a healthy fine. Hopefully people begin to take the seriousness of this virus (bioweapon). The catholic priest here in a very small town just brought it back from his trip to Spain. Nice...

Quick update: leak down test only showed one cylinder, Stb engine #7 hole had 14% leakage through exhaust valve. All other's were at 8% or less Going to pull QJ carbs and rebuild them and run it for the season. Will pull heads in the Fall, do a refresh on the heads and decide whether or not to go further into the blocks. I also removed the 20* advance modules and installed 24* modules off of 454 mags. Set initial timing back to 10*. Full advance (34*) in at < 4000 RPM.

If you can have heads gone through great. If not at the very least take a peak at the valve with a bore scope and compare to a couple others. Concentrate along the edge of the valves. Very quick and easy. 14% not that bad considering hours. I'd probably do all at once in the fall with rebuilds and heads unless valve is noticeable. Probably valve/seat combo. Only saying this is because of the way you run and maintain the boat. Jmo.

7 and 8 will typically run hotter. In my experience it's 8 but the combo/build will dictate.

I had 2 1992 502 mags that had over 800 hard hours on them the lower ends were excellent when they were dissasembled the valves were a little beat up but the engines werein great health the only real wear were the bronze bushings in the distributoris were egg shaped and wore out .I had scrorpion racing engines turn them into 540s they made 608hp 620 ftlbs

With only having one cylinder at 14%, I wouldn't even worry about doing top ends.
A friend at LOTO had 1200+hrs on stock 502mags before he had them gone through and they still were running fine.
He did replace the Qjets with Holley carbs a couple years prior.

I did rebuild the quads, they are not leaking extra fuel into the motors now. Seem to be running smoother. Did not want to go the Holly route without different intakes. I did pull off the exhaust riser on the cylinder with the 14% leak, did not find any cracks in the manifold, replaced gasket and riser. Re-torqued other risers, which were somewhat loose, going to leave it as is for now. I would still like to see what a good combination of cams, head work, intakes/carbs would work with Gill exhaust for down the road if I get inside these motors. Just figured if I decided to refresh motors, might as well add a little extra.