Thread: 348 get or not

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I found a 58 - 348 - 3751872 coded 57. Should I pick it up, it has a 4 bbl, with good valve covers if nothing else! It is at the crusher yard and will eventually be crushed. I guess I was wondering if it can be bored or stroked to a 409 and be able to get a little perfomance out of it. Could probably get it for $100 or $150.

Those 358, 421, etc are getting harder to find, def worth it, if you can get
it for that price

I don't think it's possible to take the 348 bore of 4.125 out to the 4.312 of the 409

There is a possibility that you are looking at a 409 instead of a 348. Print out the following info and take it with you to inspect the motor. Even if it turns out to be a 348, it's a score at the money you mentioned.
http://www.show-cars.com/numbers1.htm

You should also know that the Mark IV crankshafts (3.76", 4.00") have the same spacing as the 348/409 cranks. By cutting the main journal diameter from 2.750" to 2.500", the crank will theoretically drop into the block. All W and Mark IV motors use the same 2.200" rod journal size and same 6.135" rod length. So, a guy might be able to drop a 454 crank in (I have no idea of the grinding involved on the block to clear the crank) and make a W-427 (4.125" X 4.000"). Or use a 396/402/427 crank and make a W-402 (4.125" X 3.760").

Probably the biggest cost in doing this would be the pistons, which would probably have to be custom made unless another member of this board knows the whereabouts of some special pistons on a shelf somewhere.

Now, having said all this, I wouldn't spend a dime on making a monster W motor. You could build any garden variety 427 or 454 and drive around any W motor you could build. What I would consider doing is to build the motor back stock and enjoy a very unusual mill under the hood.
http://www.show-cars.com/enginekits.html

There are quite a few cams available for the W, here's a nice list..
http://www.show-cars.com/campage.html

W pistons....
http://www.bruneauperformance.ca/409...gineparts.html
I might talk to these guys about a very low compression piston (8.0:1) and mount a turbo with blow-through carb. A W-348 would think it was 500 inches with a turbo at moderate boost (6-8 psi).

Originally Posted by techinspector1

There is a possibility that you are looking at a 409 instead of a 348. Print out the following info and take it with you to inspect the motor. Even if it turns out to be a 348, it's a score at the money you mentioned.
http://www.show-cars.com/numbers1.htm

You should also know that the Mark IV crankshafts (3.76", 4.00") have the same spacing as the 348/409 cranks. By cutting the main journal diameter from 2.750" to 2.500", the crank will theoretically drop into the block. All W and Mark IV motors use the same 2.200" rod journal size and same 6.135" rod length. So, a guy might be able to drop a 454 crank in (I have no idea of the grinding involved on the block to clear the crank) and make a W-427 (4.125" X 4.000"). Or use a 396/402/427 crank and make a W-402 (4.125" X 3.760").

Probably the biggest cost in doing this would be the pistons, which would probably have to be custom made unless another member of this board knows the whereabouts of some special pistons on a shelf somewhere. .

the 454 crank will work and you can use the gm 3/8 454 thumb rods and the 454 crank nose needs to be cut down to use the 348/409 chain set or re work the timing cover for the bigger seal and the 454 damper? 454 chain set may work????? you will have to do some tin work and graft a 454 cover seal part to the w cover for the bigger seal the pistons any one can make but i think Ross sells them for the 409 shelf piston with the 4.000 but the 348 may be not you would have to call them

I love the W motors, both the 348 and 409. They just look so cool in a car, and dress up so pretty, especially with multiple carbs.

If it turns free I would grab it. I think the 409 is somehow different to get those additional cubes, so I don't know either if you can make one out of a 348.

Don

Originally Posted by Itoldyouso

I love the W motors, both the 348 and 409. They just look so cool in a car, and dress up so pretty, especially with multiple carbs.

If it turns free I would grab it. I think the 409 is somehow different to get those additional cubes, so I don't know either if you can make one out of a 348.

Don

From what I've read, you'll hit water before you get there. The 348 and 409 blocks were different castings.

Here's a pic of a 348 in my 60 Biscayne. riginal except for the air clraners

they sell alluminum heads for 348/409 now