SBC 327 Block casting number 3959512

SGSST109E · 01-09-2009, 10:39 PM

The casting number is for a 62-67 327. The block was a special thick wall casting that went out to to select racers in the 60's. I used it in C/SM in the late 70's. Still 4.001 bore, never damaged. Been sitting in my garages as I have moved for almost 30 years. What is it worth in todays world?

james schaechter · 01-09-2009, 10:56 PM

Who knows, but certainly intersting. Here is an example of one that sold on ebay. If you could sonic check it and know how thick, that might just help the price out.

http://cgi.ebay.com/ebaymotors/350-h...41310005r16371

SGSST109E · 01-09-2009, 11:54 PM

The date code on the block is "I 10 4" should mean Sept. 10th day 1964. Does anyone know what a great wall thickness would be be on a stock 4" block?

Dwight Southerland · 01-10-2009, 08:59 AM

A lot of those blocks were used as replacement pieces and found in HD trucks in '66 & '67. The description on the eBay is accurate for the machined crankcase, longer main cap bolts and spin on filter. I had two when I raced the '67 Z28 and they were more "solid" than any other block I evaluated. The two I had also had nodular iron main caps.

Greg Reimer 7376 · 01-10-2009, 11:57 AM

The 512 block was a service replacement block.Some had date codes as late as 69 or70. Some,I've been told were large journal,so be careful there. We've used them in our 327 stockers, and they do show up from time to time,so they aren't that rare if your search is diligent enough.The oil filter area is machined for a screw on filter(68 on), and some of the features on the block resemble early large journal 350 blocks. Chevrolet used to offer three stages of replacement engine- a fitted block,which came with the block,main bearings,pistons,pins,and rings with cam bearings already installed. A partial engine was a short block,sometimes with a camshaft and timing gears and cover installed,and a complete engine came with the short block,oil pump,pan,heads,valve train and covers installed.It's possible that 512 blocks came in all three configurations. The 512 is a good part if you can find it,other than the small journal crank diameter, there is probably not much advantage to scouring the earth to find one. A large journal 327 can use the stronger 350 rod forgings and 350 010/020 blocks are still much more common.The 010/020 block in my Chevelle originally started life in my 71 El Camino that I had years ago.

SGSST109E · 01-11-2009, 01:05 AM

The 512 block I have is a spin on oil filter. It is small journal. I will get it sonic tested, I believe it is a very heavy wall.

01-09-2009, 10:39 PM	#1
SGSST109E Member Join Date: Jun 2007 Location: NJ Posts: 342 Likes: 54 Liked 124 Times in 58 Posts	SBC 327 Block casting number 3959512 The casting number is for a 62-67 327. The block was a special thick wall casting that went out to to select racers in the 60's. I used it in C/SM in the late 70's. Still 4.001 bore, never damaged. Been sitting in my garages as I have moved for almost 30 years. What is it worth in todays world?

01-09-2009, 10:56 PM	#2
james schaechter VIP Member Join Date: Dec 2004 Location: Cumming GA Posts: 1,928 Likes: 1,071 Liked 1,212 Times in 249 Posts	Re: SBC 327 Block casting number 3959512 Who knows, but certainly intersting. Here is an example of one that sold on ebay. If you could sonic check it and know how thick, that might just help the price out. http://cgi.ebay.com/ebaymotors/350-h...41310005r16371 __________________ James Schaechter 3163 STK

01-09-2009, 11:54 PM	#3
SGSST109E Member Join Date: Jun 2007 Location: NJ Posts: 342 Likes: 54 Liked 124 Times in 58 Posts	Re: SBC 327 Block casting number 3959512 The date code on the block is "I 10 4" should mean Sept. 10th day 1964. Does anyone know what a great wall thickness would be be on a stock 4" block?

01-10-2009, 08:59 AM	#4
Dwight Southerland VIP Member Join Date: Dec 2001 Location: Arkansas - In the middle of everything. Posts: 1,980 Likes: 53 Liked 724 Times in 177 Posts	Re: SBC 327 Block casting number 3959512 A lot of those blocks were used as replacement pieces and found in HD trucks in '66 & '67. The description on the eBay is accurate for the machined crankcase, longer main cap bolts and spin on filter. I had two when I raced the '67 Z28 and they were more "solid" than any other block I evaluated. The two I had also had nodular iron main caps.

01-10-2009, 11:57 AM	#5
Greg Reimer 7376 VIP Member Join Date: Nov 2008 Location: Glendora,Calif. Posts: 1,111 Likes: 164 Liked 649 Times in 208 Posts	Re: SBC 327 Block casting number 3959512 The 512 block was a service replacement block.Some had date codes as late as 69 or70. Some,I've been told were large journal,so be careful there. We've used them in our 327 stockers, and they do show up from time to time,so they aren't that rare if your search is diligent enough.The oil filter area is machined for a screw on filter(68 on), and some of the features on the block resemble early large journal 350 blocks. Chevrolet used to offer three stages of replacement engine- a fitted block,which came with the block,main bearings,pistons,pins,and rings with cam bearings already installed. A partial engine was a short block,sometimes with a camshaft and timing gears and cover installed,and a complete engine came with the short block,oil pump,pan,heads,valve train and covers installed.It's possible that 512 blocks came in all three configurations. The 512 is a good part if you can find it,other than the small journal crank diameter, there is probably not much advantage to scouring the earth to find one. A large journal 327 can use the stronger 350 rod forgings and 350 010/020 blocks are still much more common.The 010/020 block in my Chevelle originally started life in my 71 El Camino that I had years ago.

01-11-2009, 01:05 AM	#6
SGSST109E Member Join Date: Jun 2007 Location: NJ Posts: 342 Likes: 54 Liked 124 Times in 58 Posts	Re: SBC 327 Block casting number 3959512 The 512 block I have is a spin on oil filter. It is small journal. I will get it sonic tested, I believe it is a very heavy wall.