What cars or trucks came with 4 bolt 350's?
09-26-2002, 04:32 PM
#1
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Join Date: Jul 2001
Location: Duluth, Ga., USA
Posts: 192
What cars or trucks came with 4 bolt 350's?
How much power will a 2 bolt handle? I would like to do a 383 stroker and possibly put a super charger on it if thats not enough. Im looking for 300-350 rwhp n/a or 400-450 sc
Thanks Kimball
Thanks Kimball
09-28-2002, 08:50 AM
#3
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Location: MD
Posts: 2,022
4 bolts only came in Corvettes and 3/4 ton trucks or larger (and a very few select hi-po applications). If you want to run a supercharger get a 4 bolt. Anything over 6000 RPM, get a 4 bolt. Anything over 450HP or so, get the 4 bolt. If you're going to spend the money to build that stroker, get the 4 bolt. And, if you can't find one - there are several aftermarket companies that make 4 bolt splayed caps for 2 bolt blocks.
2 bolt blocks a still quite strong though. It's just with the more bolts, the caps are much stronger - meaning less deflection and longer engine life. That's why Chevy put them in the Vettes and heavy-duty trucks.
If you're not building a hyd. roller...
Look at trucks from 70-85 (you won't find a Vette
). If it's got 8 or more lug nuts on the wheels, it should be a 3/4 ton or larger. And look for a 010 block. Check the casting number behind the driver's head. The last 3 should read 010. Unfortunately, not all 010's are 4 bolt. The only 100% sure way to tell is to pull the pan.
2 bolt blocks a still quite strong though. It's just with the more bolts, the caps are much stronger - meaning less deflection and longer engine life. That's why Chevy put them in the Vettes and heavy-duty trucks.
If you're not building a hyd. roller...
Look at trucks from 70-85 (you won't find a Vette
). If it's got 8 or more lug nuts on the wheels, it should be a 3/4 ton or larger. And look for a 010 block. Check the casting number behind the driver's head. The last 3 should read 010. Unfortunately, not all 010's are 4 bolt. The only 100% sure way to tell is to pull the pan.
Last edited by Marc 85Z28; 09-28-2002 at 08:59 AM.
09-28-2002, 07:06 PM
#4
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Join Date: Aug 2000
Location: Gamaliel, KY USA
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4-bolt main 350s have come in many different lines of Chevy cars, trucks and GMC trucks.
In model year 1969, through model year 1970, almost every 300 horsepower-350 engine I've torn down had four-bolt mains (more than a few had steel cranks). These engines had four-barrel carbs (cast-iron intakes) and the double-hump heads with bolt-holes for accessories.
The 300 horse-350 was available in Impalas, Caprices, Camaros, Novas, Chevelles AND Corvettes along with Chevy and GMC trucks.
The 350 engines rated above 300 horse also came with four-bolt mains. These were available in Camaros and 'Vettes (think LT-1s) in 1970 and through 1973 (although ratings method changed in 1972).
After model year 1970, you will have best chance of finding a four-bolt main in a Chevy or GMC truck.
Contrary to an above post, four-bolt mains WERE available in 1/2-ton trucks. To my experience, it seems luck of the draw on that chance.
As to strength of the two-bolt block, the earlier model year-the better. The 1967 to 1971s seem to be better made, especially the 1969 and 1970 versions. Look for core shift at the front cam bearing. A good indicator.
I've built many two-bolt 350s and not had a problem with mains.
jms
In model year 1969, through model year 1970, almost every 300 horsepower-350 engine I've torn down had four-bolt mains (more than a few had steel cranks). These engines had four-barrel carbs (cast-iron intakes) and the double-hump heads with bolt-holes for accessories.
The 300 horse-350 was available in Impalas, Caprices, Camaros, Novas, Chevelles AND Corvettes along with Chevy and GMC trucks.
The 350 engines rated above 300 horse also came with four-bolt mains. These were available in Camaros and 'Vettes (think LT-1s) in 1970 and through 1973 (although ratings method changed in 1972).
After model year 1970, you will have best chance of finding a four-bolt main in a Chevy or GMC truck.
Contrary to an above post, four-bolt mains WERE available in 1/2-ton trucks. To my experience, it seems luck of the draw on that chance.
As to strength of the two-bolt block, the earlier model year-the better. The 1967 to 1971s seem to be better made, especially the 1969 and 1970 versions. Look for core shift at the front cam bearing. A good indicator.
I've built many two-bolt 350s and not had a problem with mains.
jms
09-29-2002, 12:25 AM
#5
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Join Date: Mar 2001
Posts: 3,249
Why not use his 91 block which is a 2 bolt if it is ok? He can get the caps to make it a 4 bolt splayed. Otherwise he has to go find a block with a 1 piece rear main seal or buy an adapter for it to work with the oil pan. Besides, I prefer the 1 piece rear.
09-29-2002, 02:23 AM
#6
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Join Date: Oct 1999
Location: chino, ca
Posts: 11
How much power will a 2 bolt handle?
For under 400 H.P. you can use 2 or factory 4 bolt. If you get over 500 H.P. or more the only way to go is 2 bolt with the splayed 4 bolt caps installed.
The last factory 4 bolt block i used pushed the main webs out the first night ( N/A 710H.P.). The factory 4 bolt block has the outer bolts drilled in the weakest point of the main webs and that's the reason a converted 2 bolt block is better.
Jerry
For under 400 H.P. you can use 2 or factory 4 bolt. If you get over 500 H.P. or more the only way to go is 2 bolt with the splayed 4 bolt caps installed.
The last factory 4 bolt block i used pushed the main webs out the first night ( N/A 710H.P.). The factory 4 bolt block has the outer bolts drilled in the weakest point of the main webs and that's the reason a converted 2 bolt block is better.
Jerry
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