305/350 How to identify? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Eyegore · 03-08-2005, 01:22 AM

Just like the question says, I know the serial number show that but what am I looking for, and how do you tell the difference between a 2 bolt and 4 bolt? I want to make sure the engine I just had dropped in is what I asked for.

Sorry to ask but the search has been disabled.

Thanks

Tom

MylilBowTie · 03-08-2005, 01:41 AM

Well if its a 305 don't worry about the 4 bolt mains, there aren't any. Unless someone has a prototype block or something. As for the 350 its really hard to say without dropping the oil pan. Only thing I can thing of is the date and suffix code. Depending on what that decodes to it may be a little easier to guess if its a 4 bolt main.

What are the codes you have now?

*1FaastC10* · 03-08-2005, 05:04 PM

no way to tell if you've got a 4 bolt without pulling the pan.

Mike76251 · 03-09-2005, 06:52 AM

Yeah........................you gotta pull the pan.
Too many "old wive's tails" about 010 blocks floating around.

*1FaastC10* · 03-09-2005, 05:22 PM

depending on who you talk to, an "010" block can be 2 different things. to most serious engine builders, "010" refers to the casting marks under the timing chain cover, which is said to be information about the composition of the block casting. to many novices, any engine that carries the casting number "3970010" is an "010" block. nothing special about a 3970010 block, just your basic 68-85 302/327/350 block.

badone07 · 03-09-2005, 07:42 PM

Actually many years ago I had a 77 Monza Spyder with a 305 and 4 bolt mains. I don't remember if it was the original motor or not because I yanked it out almost immediately. The car was from Canada and stock.

010's were from 69-80, which the older years are supposed to have a higher nickel and tin content. I have them in both versions (2 bolt and 4 bolt). well actually one of the 2 bolts I presently have, I splayed to 4 bolts. Like said earlier, you have to pull the pan.

btw, my 84 350 4 bolt has 010 cast in the timing chain area. however, i forget it's casting number.

*1FaastC10* · 03-09-2005, 09:35 PM

Quote:

Originally Posted by badone07

010's were from 69-80, which the older years are supposed to have a higher nickel and tin content. I have them in both versions (2 bolt and 4 bolt). well actually one of the 2 bolts I presently have, I splayed to 4 bolts. Like said earlier, you have to pull the pan.

according to www.mortec.com this is true. however, i have owned 2 that were post-80 (verified by VIN on the passenger side deck) carrying the 3970010 casting number. both had passenger passenger side dipsticks as well, which further supports the post-80 vintage of the block.

badone07 · 03-09-2005, 11:14 PM

I'm sure anything is possible and nothing surprises me with dates and castings anymore. I've built many and personally, I haven't come across a passenger side dipsticked, 010 stamped bellhousing block. Maybe one I will.

I've also only seen one factory 4 bolt 305 in my life, which I owned, while others claim they don't exist. Back then no internet, no pics, I didn't care if it was special or not, it was coming out for a destroked 400 (377).

CHEVYE · 03-09-2005, 08:13 PM

don`t forget the newer blocks. it may have 5.0 or 5.7 stamped back there too. you can`t mistake those.

03-08-2005, 01:22 AM	#1
Eyegore What Hump? Join Date: Apr 2003 Location: New River AZ Posts: 2,009	305/350 How to identify? Just like the question says, I know the serial number show that but what am I looking for, and how do you tell the difference between a 2 bolt and 4 bolt? I want to make sure the engine I just had dropped in is what I asked for. Sorry to ask but the search has been disabled. Thanks Tom __________________ Lil red 86 c-10 99 Sub 78 Camper Special w/ 454

03-08-2005, 01:41 AM	#2
MylilBowTie Right turn Clyde Join Date: Nov 2002 Location: Cincinnati, Ohio Posts: 2,911	Well if its a 305 don't worry about the 4 bolt mains, there aren't any. Unless someone has a prototype block or something. As for the 350 its really hard to say without dropping the oil pan. Only thing I can thing of is the date and suffix code. Depending on what that decodes to it may be a little easier to guess if its a 4 bolt main. What are the codes you have now? __________________ 1974 C25 LWB: 454 4bbl Carb / TH400 / 3.73 1992 Camaro RS 305 TBI

03-09-2005, 07:42 PM	#6
badone07 Project 2 Resume Join Date: May 2004 Location: Jim Thorpe, PA Posts: 884	Actually many years ago I had a 77 Monza Spyder with a 305 and 4 bolt mains. I don't remember if it was the original motor or not because I yanked it out almost immediately. The car was from Canada and stock. 010's were from 69-80, which the older years are supposed to have a higher nickel and tin content. I have them in both versions (2 bolt and 4 bolt). well actually one of the 2 bolts I presently have, I splayed to 4 bolts. Like said earlier, you have to pull the pan. btw, my 84 350 4 bolt has 010 cast in the timing chain area. however, i forget it's casting number. __________________ John 1984 C30 Chevy Crew Cab Dually 1998 Jeep Cherokee 4x4 2004 Chevy Trailblazer 4x4 (wife's) 1970 Mustang FB fully tubed (getting 521 BBF & powerglide) 1978 Nova 2dr (going BBCaddy & S.P. th400) 1984 Monte SS (circle track car)

03-09-2005, 11:14 PM	#8
badone07 Project 2 Resume Join Date: May 2004 Location: Jim Thorpe, PA Posts: 884	I'm sure anything is possible and nothing surprises me with dates and castings anymore. I've built many and personally, I haven't come across a passenger side dipsticked, 010 stamped bellhousing block. Maybe one I will. I've also only seen one factory 4 bolt 305 in my life, which I owned, while others claim they don't exist. Back then no internet, no pics, I didn't care if it was special or not, it was coming out for a destroked 400 (377). __________________ John 1984 C30 Chevy Crew Cab Dually 1998 Jeep Cherokee 4x4 2004 Chevy Trailblazer 4x4 (wife's) 1970 Mustang FB fully tubed (getting 521 BBF & powerglide) 1978 Nova 2dr (going BBCaddy & S.P. th400) 1984 Monte SS (circle track car)

03-09-2005, 08:13 PM	#9
CHEVYE my gas saver Join Date: Sep 2003 Location: Clarksville, TN Posts: 2,046	don`t forget the newer blocks. it may have 5.0 or 5.7 stamped back there too. you can`t mistake those. __________________ 85' SWB, 4.3/TH350, getting ready for paint 84`SWB, 462ci./TH400, cowl hood, 15" billet spec., flows, blazer buckets/console, flat black 71`SWB, project ebay feedback

03-08-2005, 05:04 PM	#3
1FaastC10 Account Suspended Join Date: Oct 2002 Location: Elkhart, IN Posts: 6,400	no way to tell if you've got a 4 bolt without pulling the pan.

03-09-2005, 06:52 AM	#4
Mike76251 Senior Member Join Date: Mar 2003 Posts: 2,500	Yeah........................you gotta pull the pan. Too many "old wive's tails" about 010 blocks floating around.

03-09-2005, 05:22 PM	#5
1FaastC10 Account Suspended Join Date: Oct 2002 Location: Elkhart, IN Posts: 6,400	depending on who you talk to, an "010" block can be 2 different things. to most serious engine builders, "010" refers to the casting marks under the timing chain cover, which is said to be information about the composition of the block casting. to many novices, any engine that carries the casting number "3970010" is an "010" block. nothing special about a 3970010 block, just your basic 68-85 302/327/350 block.



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