converting 2 bolt to 4 bolt
Le Mans Master
Joined: May 2007
Posts: 5,028
Likes: 1,120
From: North tonawanda NY
Yeah this has been covered a bunch of times and there is evidence that goes both ways..I found no. "Without a doubt evidence so if you have it please share . I had a conversation with a machinist who says otherwise.... apparently the "502" 010 and 020 blocks are bitch on his equipment and make a noticeably different sound when being machined. Also if you Google it there is a thread out there where a retired gm engineer actually contributed evidence that The marking originally were for the higher nickel blocks GM was experimenting with and then abandoned and if the blocks have both 502 and the 010 and 020 markings they are indeed the higher nickel/tin regardless I didn't know about it when I bought the engine.
Last edited by augiedoggy; May 8, 2013 at 10:02 PM.
Burning Brakes
Joined: Jun 2009
Posts: 840
Likes: 4
From: Syracuse IN
Why even waist your time and money on a non original block. A brand new ZZ4 rotating assy, which is already a 4 bolt main and much better casting, cost is roughly $1,750.00 Machining and parts for an old 350 rebuild properly will cost the same or more. Al
Melting Slicks
Joined: May 2002
Posts: 2,717
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
If you want the 4 bolt block than bring it to a reputable shop and have them supply the caps, drill and thread the holes and line bore to true everything up. the cost is minimal and will strengthen the block.
Its your motor, do it if its what you want.
The machining will not weaken the block,
The 4 bolt caps will without doubt strengthen the engine.
Neal
Its your motor, do it if its what you want.
The machining will not weaken the block,
The 4 bolt caps will without doubt strengthen the engine.
Neal
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
Le Mans Master
Joined: May 2007
Posts: 5,028
Likes: 1,120
From: North tonawanda NY
My build is mild but should have over 400lbs of torque and be somewhere around 360-370 HP.... and everything but the Carb I already had cost about 1,200 at this point and that's because I splurged on polished intake and water pump and pulleys plus the other bling like a chrome alternator case for my old alternator and yes even the cheesy stainless hose covers and "boy racer" gear reduction starter... It has older iron eagle heads with harland 1.5 roller rockers..... so it is possible to build on a budget.... Craigslist and eBay helped a lot...
Race Director
Joined: Jan 2000
Posts: 13,018
Likes: 2,262
From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
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4 bolt 350's are very plentiful. Just find one of them to start with and save a lot of expense.
JIM
JIM
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Le Mans Master
Joined: May 2007
Posts: 5,028
Likes: 1,120
From: North tonawanda NY
I read it in November while I off hunting.... not going to search for it now..... I do live in North tonawanda ..... I could ask the guys at the engine plant engineering next time I'm there since they are one Of my clients. I,m pretty sure I rated the high nickel blocks only came from the flint plant and not sure how knowledgeable they would be about something 40 years later they don't even know the manufacturing statistics from back then..... The crappy part is I had a retired friend who worked in the engineering dept years ago and he used to bring up stuff like the manufacturing tolerences at gm and such when we were talking about bikes but he passed away.
Besides I asked you for your proof first :-)
Besides I asked you for your proof first :-)
Last edited by augiedoggy; May 9, 2013 at 07:16 AM.
Race Director
Joined: Jan 2002
Posts: 11,615
Likes: 350
From: No Where USA
Are you doing this because you are going to use this motor to race the car or just to say you have a 4 bolt main motor.
I have run 10 seconds with a 2 bolt main big block. I just studded the caps and used all ARP hardware on the rode and the studs.
I have run 10 seconds with a 2 bolt main big block. I just studded the caps and used all ARP hardware on the rode and the studs.
Drifting
Joined: Oct 2012
Posts: 1,524
Likes: 61
From: Medina Ohio
Don't forget that when adding main studs like many have mentioned, that it is recommended to have the mains align honed/bored.
I will also agree that you'd be better off just buying a 4 bolt block, and highly recommend getting an 87+ roller block. I just picked one up for $80.
I will also agree that you'd be better off just buying a 4 bolt block, and highly recommend getting an 87+ roller block. I just picked one up for $80.
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
I read it in November while I off hunting.... not going to search for it now..... I do live in North tonawanda ..... I could ask the guys at the engine plant engineering next time I'm there since they are one Of my clients. I,m pretty sure I rated the high nickel blocks only came from the flint plant and not sure how knowledgeable they would be about something 40 years later they don't even know the manufacturing statistics from back then..... The crappy part is I had a retired friend who worked in the engineering dept years ago and he used to bring up stuff like the manufacturing tolerences at gm and such when we were talking about bikes but he passed away.
Besides I asked you for your proof first :-)
Besides I asked you for your proof first :-)
http://forums.corvetteforum.com/c3-t...kel-block.html
or to save time and cut to the chase just read the last two posts. The 010, 020 and 509 are the last three digits of the block casting numbers, nothing more.
Le Mans Master
Joined: May 2007
Posts: 5,028
Likes: 1,120
From: North tonawanda NY
Your info is way off and it sounds like you've put faith in the myth as much as everybody else. Read here:
http://forums.corvetteforum.com/c3-t...kel-block.html
or to save time and cut to the chase just read the last two posts. The 010, 020 and 509 are the last three digits of the block casting numbers, nothing more.
http://forums.corvetteforum.com/c3-t...kel-block.html
or to save time and cut to the chase just read the last two posts. The 010, 020 and 509 are the last three digits of the block casting numbers, nothing more.
If anything there is more personal testimonials and evidence saying there were some higher nickel blocks .... mainly from the late 60's and into the mid 70's that may have had the higher nickel as Gm was experimenting with the metals.... and if that were true it would certainly make total sense for GM not to want to admit to any of this...I see this type of thing done all the time with the manufacturers I deal with..you would have better luck getting GM to admit that the cold air intake on the Corvette was more marketing tool then functional. They will avoid liability and blame by just not acknowledging things.
I still see no real proof either way... just a hell of a lot people believing the "Myth" and many being convinced with their own experiences...
And the "010,020,509 numbers are not just the last three digits of the block casting #...... My block has all three of those markings embossed separately under the timing chain cover.
Last edited by augiedoggy; May 9, 2013 at 11:34 AM.
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
Please re-read the post. You seem to have glossed over the various statements from the GM employees clearly explaining the real meaning of the numbers.
casting numbers:
3970010
3790020
3951509
numbers under the timing chain cover
010
020
509
yes, there were various changes in metallurgy over the years- but these are not connected to any numbers under the cover or anywhere else.
Le Mans Master
Joined: May 2007
Posts: 5,028
Likes: 1,120
From: North tonawanda NY
Pot calling kettle black.
Please re-read the post. You seem to have glossed over the various statements from the GM employees clearly explaining the real meaning of the numbers.
casting numbers:
3970010
3790020
3951509
numbers under the timing chain cover
010
020
509
yes, there were various changes in metallurgy over the years- but these are not connected to any numbers under the cover or anywhere else.
Please re-read the post. You seem to have glossed over the various statements from the GM employees clearly explaining the real meaning of the numbers.
casting numbers:
3970010
3790020
3951509
numbers under the timing chain cover
010
020
509
yes, there were various changes in metallurgy over the years- but these are not connected to any numbers under the cover or anywhere else.
as far as the pot calling the kettle black maybe ,but then who's better qualified to make that assumption
Last edited by augiedoggy; May 9, 2013 at 11:52 AM.
Instructor
Joined: Jul 2010
Posts: 120
Likes: 0
I've built a fair amount of stock and non stock motors. I wouldn't do the conversion unless its a numbers matching block other wise go ahead. Go with the studs instead. My thinking is the machinist may not have the confidence of know how to do this so its easier to try to scare you away from doing it.
Drifting
Joined: Jan 2012
Posts: 1,908
Likes: 129
From: Fredericksburg Virginia
Agree. ARP Studs on a 2-Bolt block is a VERY solid way to go for a 500 HP or below build.
Unless you go with a huge stroke or pressurization (supercharger), that takes some sincere effort to get horsepower that high.
Not impossible...you just need to build it like you mean it.
Unless you go with a huge stroke or pressurization (supercharger), that takes some sincere effort to get horsepower that high.
Not impossible...you just need to build it like you mean it.
Racer
Joined: Jan 2007
Posts: 427
Likes: 1
I have logged on 87.5 miles on a 2 bolt main 355" 350 on the drag strip with 6400 RPM shifts and had absolutely no problems with ARP hardware. This engine is waiting a 'ring job' and install into a 1960 Chevy pickup.
I used to get a kick out of all the stories about the legendary '327'. From my expereince that engine was only a two bolt main and ran very well.
IMHO, don't get all caught up in the hype. I too fell for everything from 'water injection' to 'vertical gate shifters' (try driving that home after having a few).
Do your research and compile your own pro's and con's.
I used to get a kick out of all the stories about the legendary '327'. From my expereince that engine was only a two bolt main and ran very well.
IMHO, don't get all caught up in the hype. I too fell for everything from 'water injection' to 'vertical gate shifters' (try driving that home after having a few).
Do your research and compile your own pro's and con's.
Drifting
Joined: Aug 2004
Posts: 1,883
Likes: 124
From: Lubbock TX
I never worked at a GM foundry, but...
My machinist buddy has honed everything under the sun for over 20 years. He said he can tell by the sound and feel when he's working on a 010/020 block.
The BHJ sonic tester I use has calibrator pieces for several different blocks including one for High Tin/Nickel Production blocks...they're the same as for Bowties. I wouldn't think they'd make a distinction if there wasn't one, even to the point of providing the calibrator piece.