401 crank in a 360

Jeepcraze

I am rebuilding my 360 for my 89 GW. It is bored .060 over w/ .010 under mains and rods. What I have decided to do is get a 401 crank and cut the rod journals to fit the 360 rods. Then I can run stock pistons and stock 360 rods, and have the stroke of the 401 crank. Beings that the crank is forged it should still be strong enough cutting it that hard on the rod side. HAs anyone ever done this, I have found a few articles on the internet about it, but wanted to talk to someone who has done it already. This is not gonna be a racer or High performance machine, this is gonna be a sunday driver/ show truck w/ a nice motor build. Now I figure that I will have to get the block clearanced for the extra stroke. I just wanna make sure I don't have any issues w/ deck height clearance issues or valve clearance. Thanks Craig

ol' school power

Increasing stroke means that the piston will be reaching further in both directions by 1/2 the amount of stroke increase. From there, figure how much the piston will be sticking out of the top of the block.

Jeepcraze

How far below the top of the cylinder is the current 360 on its stroke?

Lifted79CJ7

I know this doesn't answer your question, but the 360 has a 3.44 stroke and the 401 has a 3.68 stroke in case anyone was wondering.

eight

Use 401 rods. If you find a 401 crank, its likely in a 401, so why not just use the whole thing?

Jeepcraze

I have a 360 sitting here already, and the cheapest I can find a 401 w/ shipping is like 600-800 bucks. So for that much money, I can stick it into a motor I have infront of me already and make it that much more of a motor. Useing the 401 rods will cause me to get custom pistons (more money) If I get the crank cut for the 360 rods then I can use stock everything. just need alittle machineing/clearancing and i'll be good to go.

1970amx

It is NOT going to be that easy. For 1 the 360 rod journal is wider than a 401 rod journal. You better make sure that you can widen the 401 rod journal to the 360 spec. You are going to have to have custom pistons anyway.....the stock ones will NOT work. They will be hanging out of the top of the cylinder bore if you use the 3.68" stroke 401 crank ! Since you MUST have custom pistons to do this crank swap you may as well use the forged 401 rods...then you wont have to worry about cutting the rod journals down to 360 size and you will have a forged rod of the 401 not a cast 360 rod. The custom pistons will cost about $600 dollars or so. In the long run it will be cheaper to get the whole 401 engine for 600-800 dollars. Rob

Jeepcraze

How come so many people make it sound so easy. I found an article on the internet that said the rods from the 360 would fit if the 401 crank was turned. I have other guys tell me that putting chevy rods and pistons in it is easy. GUess one man's easy is another mans hard. Guess I need to talk to my machinst and see if he feels comfortable doing all that cutting and re figuring.

tufcj

Look at this thread in the "how-to tech" area. It's on stroking a 401. Lots of good discussion on stroke, deck height, compression height, and pin placement, all which have to be calculated in any stroker motor.

http://www.bulltear.com/forum/viewtopic.php?t=1473

I've never done a stroker, but I think that since the 401 has a longer stroke, it uses a shorter rod, since the deck height on both blocks is the same. Using a longer 360 rod with the 401 stroke would put the piston up above the block at the top of the stroke.

Bob
tufcj