360 Block/401 Crank

[Tigger]

Getting a crank kit with the crank is almost as cheap as getting a crank turned, what are the pros and cons of putting a 401 crank in a 360 block that will be .040 over. which rods would you use the 360 or the 401? I am used to building the I6 Strokers but the V8 stuff is new.

discuss

[Lifted79CJ7]

Well, I remember the moderator at www.Froadin.com had some info on this, and here is what I borrowed from his tech site:

"Any crank will fit into any block.
(Clearancing required to put 401 or 390 cranks in the 290 or 304 blocks)"

"A 401 crank in a 360 block is a good combo. It ressembles the Chevy 383 set-up. But a little bigger, 385, without boring, and 390 at .030 over. But needs special made pistons or bushed pin holes in the rods."

"The various overbore capabilities allow the use of many different pistons.
ie. Chevy 305 pistons fit in a 304 block to give you 311 ci. Chevy 400 pistons fit in a 360 block, and while this only gives you 367.7 ci., this combination with a 401 crank gives you a 393.4 ci. Many more combinations are availible. Please note that these combos are with machine work, and are not just drop in."

I would have posted the links, but they all come up the same. I hope this helps!
Jack

[Tigger]

That link is where I got the idea from. Figured some of the AMC V8 Guru's could shed more light on the details and if its a good idea or not.

[diddycj5]

I was just starting to look into the same thing... I have 2 360 blocks for one rebuild project but like the idea of stroking it and having a fordged crank. What is different about the pistons that you can't use 401 crank/rods & 360 pistons? Aren't 401 rods fordged also?

[jeepsr4ever]

you can build a AMC 385 that way or a wild stroked 360 depending if you stay with the stock strok of the 401 crank

[Tigger]

Do you have to go with custom pistons or would a good set of 360 pistons. Do you use the 360 or the 401 rods?

[Tigger]

hmmmm no answers for my questions.... come awn guys help me make a V8 stroker.

[Lifted79CJ7]

Simple, just measure the rods, pistons and crank and do the math. I think you have to get custom pistons. I remember reading that somewhere so that you can clear the heads. I could be wrong, though. I would say use 401 rods since they are forged. If they don't fit, then drink lots of beer. I know none of this really helps right now, but I will see what I can dig up tomorrow for ya.

[Tigger]

A 360 with a 401 crank and .040 overbore works out to be a 392 Stroker.

I don't have 401 pistons to measure and compare to 360's, can someone help me with that information?

Connecting Rod Length:
360 - 5.875
401 - 5.858
Difference - 0.017 (401 being less)

I know in the 4.7L I6 Stroker you use the shorter 4.2 rods with the larger stroke of the 4.2 crank so you don't have clearance problems with the head as well as compression that is way out of sight and you use stock 4.0 pistons (you can dish them to lower compression even more). I am thinking it would be the same with the 360, use 401 Crank/Rods and standard 360 compression overbore pistions. I was told with a 4.7L Stroker that you had to use custom pistons also but never had to using the 4.2 crank/rods

Deck height:
360 - 9.208
401 - 9.208

Cylinder head volume:
360 - 5.792 cc
401 - 5.792 cc

Deck clearance:
360 - 0.012
401 - 0.002
Difference - 0.010 (401 being less)
If you take the connecting rod length difference Deck clearance becomes a .007 difference, making the Deck Clearance 0.009 closer to stock 360.

[FSJnovice]

=D> How deep in the hole will the piston be? How much compression will you have? Sounds good and looks like it will work, mock it up and post pics. Just to see how the reciprocating assembly actually moves with or without binding remember pics.