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L31 help!!!

Old 04-04-2012, 08:45 PM
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L31 help!!!

im buying an L31 engine off my buddy thats coming out of his 96 suburban. iv read some where that the 1500 engines are better to have than the 2500 engines but can i ask why and what the problem is and the difference is???. as far as i can tell its just a 5.7 350 vortec thats producing like 340 hp, correct?
Old 04-05-2012, 06:43 AM
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Re: L31 help!!!

IIRC, some of the 906 heads from the 2500 up trucks had hardened valve seats with a single angle cut valve. They tend to not flow as good in stock form.

A refresh with a 3 angle cut should negate all of that.

According to wikipeida, the stock 5.7 was rated at 255 hp. I know it aint 340 in stock form.
Old 04-05-2012, 07:02 AM
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Re: L31 help!!!

But the 2500 blocks are better because they are 4 bolt main.
Old 04-05-2012, 07:17 AM
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Re: L31 help!!!

Not that it matters at all at any horsepower level that a mostly stock 350 will ever produce.
Old 04-05-2012, 07:42 AM
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Re: L31 help!!!

Oh I know just stating that it is a better block in general. But yeah doesn't really matter even on a fairly wild build.
Old 04-05-2012, 10:01 AM
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Car: 1986 camaro Sports Coupe
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Re: L31 help!!!

Originally Posted by 3rdgenmaro
IIRC, some of the 906 heads from the 2500 up trucks had hardened valve seats with a single angle cut valve. They tend to not flow as good in stock form.

A refresh with a 3 angle cut should negate all of that.

According to wikipeida, the stock 5.7 was rated at 255 hp. I know it aint 340 in stock form.
The Vortec 5700 produces 255 hp (190 kW) to 350 hp (261 kW) at 4600 rpm and 330 lb·ft (447 N·m) to 350 lb·ft (475 N·m) of torque at 2800 rpm
Old 04-05-2012, 10:33 AM
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Re: L31 help!!!

There is no stock automotive application in which the L31 produces that kind of horsepower regardless of what your source says.

Last edited by Jim85IROC; 04-05-2012 at 10:48 AM.
Old 04-07-2012, 10:09 AM
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Re: L31 help!!!

Originally Posted by evilemokid94
The Vortec 5700 produces 255 hp (190 kW) to 350 hp (261 kW) at 4600 rpm and 330 lb·ft (447 N·m) to 350 lb·ft (475 N·m) of torque at 2800 rpm
If you are going to quote from anything, you need to read the rest of the paragraph to see exactly what it is saying.

You left off: "It is currently being produced as a crate engine for marine applications and automotive hobbyists as the "ramjet 350" with minor modifications."

Notice the piece about the Ramjet 350?
http://www.summitracing.com/parts/NAL-12499120

There is your 350hp application.
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