350 Sleeve or 305 block

STR001 · 10-03-2016, 09:10 PM

I currently have a 86 Camaro with a 350/330 crate motor that I run in IHRA stock eliminator. I am thinking about building a 305 engine so I can run some in the NHRA. Is it legal to sleeve a 350 block to make a 305? Or do you have to use a true 305 block? I have heard conflicting answers. I have been unable to find this information in writing anywhere. Thanks in advance. Jason Tucker

Alan Roehrich · 10-03-2016, 09:25 PM

Yes, you can legally sleeve a 350 block down to 305 bore size.

STR001 · 10-03-2016, 10:14 PM

Alan,
Thanks for the quick response. Jason

tj310 · 10-04-2016, 09:39 AM

Two bolt mains only as the 305 was never available with four bolt ...Trevor

Ed Wright · 10-04-2016, 02:07 PM

They count main cap bolts in Stock?

rod butcher · 10-04-2016, 03:06 PM

The Dart 305 block is 4 bolt mains and I was told is legal for stock? The small bore bowtie 182 block is 2 bolt main and also legal but very hard to find. The 305 block # 627 filled is a good option.

rod butcher

Tim H · 10-04-2016, 07:28 PM

Slightly off topic but aren't many 396 racers using sleeved more common 454 blocks ?

Greg Reimer 7376 · 10-04-2016, 07:30 PM

If the Dart block is an accepted product, there's no problem with running it. I think you would be lots further ahead by buying one and doing it up. How many stock blocks do you have to go through before you find one that sonic tests OK, is crack free, is not core shifted,etc. before you can go ahead and use it? If you have to reject 4 or 5 OEM blocks before you get a good one, you spent enough on the rejects to pay for a Dart block. One thing about the Dart block-it's heavy. They don't seem to care about the main caps,however.

Alan Roehrich · 10-04-2016, 07:40 PM

Quote:

Originally Posted by Tim H

Slightly off topic but aren't many 396 racers using sleeved more common 454 blocks ?

Some, yes, I have one. But the Dart block is the way to go, the only drawback is weight. If I did not already have the prepped 454 block left over from a 427, I'd have bought a Dart.

Rick Leininger Jr. · 10-05-2016, 01:03 PM

Quote:

Originally Posted by Tim H

Slightly off topic but aren't many 396 racers using sleeved more common 454 blocks ?

Yes, been happening for decades.

10-03-2016, 09:10 PM	#1
STR001 Junior Member Join Date: Jan 2012 Location: Claxton, Georgia Posts: 55 Likes: 0 Liked 0 Times in 0 Posts	350 Sleeve or 305 block I currently have a 86 Camaro with a 350/330 crate motor that I run in IHRA stock eliminator. I am thinking about building a 305 engine so I can run some in the NHRA. Is it legal to sleeve a 350 block to make a 305? Or do you have to use a true 305 block? I have heard conflicting answers. I have been unable to find this information in writing anywhere. Thanks in advance. Jason Tucker

10-03-2016, 09:25 PM	#2
Alan Roehrich VIP Member Join Date: May 2006 Location: Murfreesboro TN Posts: 4,915 Likes: 996 Liked 1,042 Times in 274 Posts	Re: 350 Sleeve or 305 block Yes, you can legally sleeve a 350 block down to 305 bore size. __________________ Alan Roehrich 212A G/S

10-03-2016, 10:14 PM	#3
STR001 Junior Member Join Date: Jan 2012 Location: Claxton, Georgia Posts: 55 Likes: 0 Liked 0 Times in 0 Posts	Re: 350 Sleeve or 305 block Alan, Thanks for the quick response. Jason

10-04-2016, 09:39 AM	#4
tj310 Member Join Date: Sep 2009 Location: Dresden On. Canada Posts: 460 Likes: 0 Liked 0 Times in 0 Posts	Re: 350 Sleeve or 305 block Two bolt mains only as the 305 was never available with four bolt ...Trevor

10-04-2016, 02:07 PM	#5
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 389 Times in 168 Posts	Re: 350 Sleeve or 305 block They count main cap bolts in Stock? __________________ Ed Wright 4156 SS/JA

10-04-2016, 03:06 PM	#6
rod butcher Member Join Date: Dec 2005 Posts: 248 Likes: 291 Liked 129 Times in 24 Posts	Re: 350 Sleeve or 305 block The Dart 305 block is 4 bolt mains and I was told is legal for stock? The small bore bowtie 182 block is 2 bolt main and also legal but very hard to find. The 305 block # 627 filled is a good option. rod butcher

10-04-2016, 07:28 PM	#7
Tim H VIP Member Join Date: Jan 2007 Posts: 1,010 Likes: 898 Liked 430 Times in 142 Posts	Re: 350 Sleeve or 305 block Slightly off topic but aren't many 396 racers using sleeved more common 454 blocks ?

10-04-2016, 07:30 PM	#8
Greg Reimer 7376 VIP Member Join Date: Nov 2008 Location: Glendora,Calif. Posts: 1,111 Likes: 164 Liked 649 Times in 208 Posts	Re: 350 Sleeve or 305 block If the Dart block is an accepted product, there's no problem with running it. I think you would be lots further ahead by buying one and doing it up. How many stock blocks do you have to go through before you find one that sonic tests OK, is crack free, is not core shifted,etc. before you can go ahead and use it? If you have to reject 4 or 5 OEM blocks before you get a good one, you spent enough on the rejects to pay for a Dart block. One thing about the Dart block-it's heavy. They don't seem to care about the main caps,however.