Hello sofa, fast355, Orr, et al

Can #059 L30 305 Vortec 58cc heads with steam holes drilled be used on a stock ‘76 #509 400 sbc short block with 93 pump gas for street use?



Stock cam, adequate radiator, outside air intake, #1014 gaskets, & adjusted timing would be addressed. Initial look tentatively has the pistons .025” in the hole.



The stock pistons have a circular dish with slight valve reliefs.



I have found that the piston dishes could be 18 cc – 22 cc in volume.



Also, instead of the usual VIN stamping deck boss below the front of the passenger cylinder head, there’s a very short square blank block devoid of any numbers.

it does not appear to be decked at all.



Maybe because it’s a dedicated RV 400 small block.



Would this head/block combination detonate itself to death or have a chance of living on the street with occasional “spirited“ driving?

Thanks

 

It'll fit and run and all that. As far as the compression being within range, ... that's gonna be kinda tough, butt depending on tuning, it might work.

It's been decked. Blee dat. Probably, just a real long time ago.

 

Thanks for the reply sofa, appreciate that.

The 400 is from a 42K mile RV. Two of the 12 exhaust manifold bolts broke off at the number one cylinder exhaust port after soaking all of them in Aerokroil for a week and a half before the attempt.