May need help diagnosing 429CJ failure

Hello. I am a long time lurker to this site and pre-site relatives.

My 429CJ bottom end came apart and (I assume) piston rod or rod cap penetrated the oil pan on the Southbound I-95, Exit 140 ramp in VA. I was accelerating in 2d gear, opened the secondaries on the Quadrajet, and had my handle on the shifter to shift to 3rd when the bottom end came loose. No tach, but my gut feel was the engine was at @3,300 RPM or less when it died.

This engine had 5,000 miles on it since rebuild 2.5 years ago, and 65,000 miles since assembled in 1969. It is in a '70 Ranchero with stock toploader and 9 inch rear. It was running great. Only discrepancies were:
1) using oil and leaking some out of the area of rear intake manifold, but oil was full when it came apart. In October, compression was btwn 210-230 on all cylinders.
2) Quadrajet leaks some gas into engine after sitting for a few days but oil didn't smell like gas
3) When I re-installed the engine after rebuild, the custom pipes angle was slightly off, leaving a @1/16 - 1/8" leak over a portion of the mating to both exhaust manifolds. The noise of the exhaust leak could have masked some rod knock noise, so not sure about that?

The engine was a stock 429CJ with exception of new bearings, and the CJ heads had been reworked with hydaulic roller lifters with new camshaft. When it was first rebuilt, it was showing strong oil pressure (86 psi) pretty much throughout the operating range, and making 403 hp @4,000 rpm and 485 ft/lb torque at @3000 rpm.

If I pull it apart, I will post pics, but that could be awhile. Not sure right now whether I will pull it apart and get it running again- seems like just awhile ago since I had engine out last time. I didn't do the rebuild but had great confidence in the man who did.

Thank you for any insights! Barry

Rod Broke?

Cylinder Pressure looks a little high for Iron heads and Pump gas, where you noticing any detonation?

Yes, I think a rod broke, but not sure until I tear into it. I never noticed any detonation, but my failure to properly mate my pipes to exhaust manifold would've masked the popping sound. When I did the compression test in October, I didn't find any "pepper" on the spark plug porcelain, but I will take them out and look again. Heading on travel for 10 days starting end of week, so won't do much until I come back. Thanks!

That's a bit much for cranking compression on pump gas..............

I'm guessing a broken rod bolt.

The only time I have broken a rod was in a 351-C with stock rods. It didn't have floating pins and the wristpin siezed up in the piston. Powdered everything between the big end and little end.