305 blocks- whats the best one to use ?

JRyan · 08-19-2007, 03:30 PM

Kenny,

Better not use a 4-bolt 350 block as a core to sleeve, as they aren't a legal replacement for a 305 (based on a call to NHRA). The 305's were all 2-bolt and that's what NHRA wants to see IF the pan ever comes off. The best block to use if you can find one is the '68, '69 307 block. Many were cored as 350's so you end up with the very thick walls of a 350 but can use a more generally available sleeve.

Jerry

08-19-2007, 03:30 PM	#6
JRyan Senior Member Join Date: Apr 2003 Location: Aberdeen SD Posts: 645 Likes: 30 Liked 112 Times in 31 Posts	Re: 305 blocks- whats the best one to use ? Kenny, Better not use a 4-bolt 350 block as a core to sleeve, as they aren't a legal replacement for a 305 (based on a call to NHRA). The 305's were all 2-bolt and that's what NHRA wants to see IF the pan ever comes off. The best block to use if you can find one is the '68, '69 307 block. Many were cored as 350's so you end up with the very thick walls of a 350 but can use a more generally available sleeve. Jerry