So I had my mind set on a 4 inch crank. A builder suggested a 4.125, but I guess he corrected himself and said that the 4.125 is to big for the iron block since the deck is shorter. Then he suggested a 4.100. What should I do? Im looking in to the callies forge cranks

4.000 or 4.100?

I know a 4.000 will make it a 408 with 4.030 what would a 4.100 make it with a 4.030 bore?

 

Bump bump

 

I agree with your initial choice. I try to keep my motors square.

 

Callies 4.000 you will have minor clearance issues but with more stroke you will have to do a lot more clearancing.

Tim

 

"the 4.125 is to big for the iron block since the deck is shorter. " Shorter than what???

 

The iron blocks have the shortest sleeve length and its said the deck is .010" shorter than the aluminum blocks (9.230" vs 9.240").

 

So my best bet would be to stick with the 4 inch crank? I also noticed that callies I beams dont come in 6.098 rods. According to him thats what I need to run this 4.100. I went a head and ordered the callies 4.100. Should I cancel and get the 4.000?

 

Honestly thats what I wanted originally. Callies 4.000 and callies I beam 6.125 rod

 

Do the 4.000" crank. I did and all my rod bolts cleared the cylinder sleeves by 0.060" or so on my iron block. The only thing I had to space/clearance is my windage tray (running truck oil pan also).

With the 4.100" crank you will have to remove material all over the inside of that block to make it clear. Not saying it can't be done, however the pistons will also wear faster because they come out of the bottom of the cylinder further.

Here is a pic of how far my pistons come out with 4" crank and 6.125" rods: