converting a 2-bolt to 4-bolt small block
Thread Starter
Pro
Joined: Sep 2002
Posts: 541
Likes: 5
From: Epping NH
converting a 2-bolt to 4-bolt small block
Looking for info/advice regarding converting a 3970010 2-bolt block to a 4-bolt block. I seem to recall reading at one time that this was not a bad idea. Any thoughts? Thanks.
Mark
Mark
Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
Re: converting a 2-bolt to 4-bolt small block (Burgandy 69)
No need to unless you think you will punish more than this 2 bolt with all stock lower end:
http://www.chevyhiperformance.com/te.../148_0303_n20/
http://www.chevyhiperformance.com/te.../148_0303_n20/
Le Mans Master
Joined: Feb 1999
Posts: 8,351
Likes: 75
From: Tampa Bay FL
Re: converting a 2-bolt to 4-bolt small block (Burgandy 69)
Save the cost of the 4-bolt conversion and instead put it in good fasteners (ARP) and other quality engine parts. Unless you are making over 500hp and planning to punish the engine regularly (1/4 mile), I'd stay with 2-bolt.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Re: converting a 2-bolt to 4-bolt small block (Burgandy 69)
If you plan on using a really hard forged crank like 4340 you need a four bolt and it's preferrable to use a studded bottom end. The harder the steel the easier they break if the main caps have any movement. That's why lessor forgings like 5140 or even cast cranks have some advantages.
IMO - You just have to justify the cost and have peace of mind in what your doing.
IMO - You just have to justify the cost and have peace of mind in what your doing.
Race Director
Joined: Dec 1999
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Re: converting a 2-bolt to 4-bolt small block (ken markusa)
if you want to convert to 4 bolt, IMO don't waste the money and get a splayed 4 setup. It's a little more costly but if you are aiming for more revs & power in the longer run you could regret going to a normal 4 bolt setup.
