blacksheep-1

OK 305's are absolute garbage and should be used only for anchors. Put a 350 in it you imbecile.
Now that the flaming is over........

Back in the day, we used to radius the block area in BBC's to unshroud the valves. As I recall, it was to put aluminum heads on a 454, but it was a while (30years)ago. Since valve shrouding seems to be a huge problem on the 305 I was wondering if anyone had tried this to deshroud the intake, or to possibly install a1.94 valve. We had to be careful not to screw up the head gasket, so here's my idea.
Use a 350 headgasket (maybe, if it fits) and deshroud the valve area in the block (above the ring land of course) Any compression loss could be recoverred by either cutting the heads or going with a shorter gasket.
Any ideas/comments?

RB83L69

It could be done, if you either could find a head gasket to accomodate it, or marked the block with a head gasket and avoided going past it.

Factory big blocks were made that way, esp. the 396; and the fire ring in the gasket had (has) a little whoop-de-do to clear it.

Also keep in mind, the chamber on a BB is taller, so the relief doesn't have to be as deep as it would on a SB, to have the same effect. Remember, the intake valve seat is just almost flush with the deck of the head, unlike the BB where it's a good .200" above the deck. The need to keep it above the rings might make the relief small enough as to be largely ineffective.

88305tpiT/A

iTrader: (2)

I did that. Machinist recommended it. I didnt take the lip back much -- really I just rolled it a little.

blacksheep-1

Yes, that's true on the BBC. I've seen the factory ones before, I had forgotten about that. You guys wouldn't have any pics or diagrams would you?