[footjoy]

I have a 400 .040 if I put a stoker crank in will I have to change rods and pistons?

I'm guessing You have to .

Thanks
Greg

[PunchT37]

You will have to change pistons to correct pin height. Then, depending on the crank in the kit, maybe rods too.

[Dragncar]

You usually run BBC rod, 6.7 or 6.8" long. To do it with a Pontiac rod would be out of the norm and cost you more money.
Most kits are with the 6.8 rod. Not sure you can even buy a "stroker" crank with Pontiac rod anymore.

[maxpowerta]

Originally Posted by Dragncar

You usually run BBC rod, 6.7 or 6.8" long. To do it with a Pontiac rod would be out of the norm and cost you more money.
Most kits are with the 6.8 rod. Not sure you can even buy a "stroker" crank with Pontiac rod anymore.

I just bought a speedmaster stroker crank that uses the pontiac sized journals last month.

[ponyakr]

The Eagle 3" main, 4.21 stroke cranks are forged, and cost over $700.

That's why most low buck stroker guys go with the 4.25 stroke cast crank assembly.

With the 4.21 stroke crank, you can use stock length Pontiac rods, & Speed Pro L2359NF pistons.

The cheaper 4.25 stroker assemblies use Eagle 5140 6.8" rods, & Mahle pistons.

https://butlerperformance.com/i-3164...tegory:1459543

[chiphead]

It depends on the rod journal diameter of the crank. Some aftermarket cranks have the Pontiac 2.250" rod journal diameter, they can be used with aftermarket Pontiac 6.625" rods. Many forged stroker cranks (like the Scat I used) have BBC 2.200" rod journals, which require BBC rods, most often in 6.7 or 6.8" lengths. Once you know the stroke, the rod length and the block's deck height, you can pick a piston pin height to fit the combination.

[David Jones]

Originally Posted by maxpowerta

I just bought a speedmaster stroker crank that uses the pontiac sized journals last month.

The question has got to be......what size journals will it use next month?

[Schurkey]

Originally Posted by David Jones

The question has got to be......what size journals will it use next month?

Or even, what size are the front of the journals vs. the rear of the journals.

Speedmaster...Woof.

[hobbygto65]

I take it nobody uses a stock 455 crank that's been ground down to 3" mains anymore?

[Will]

Originally Posted by hobbygto65

I take it nobody uses a stock 455 crank that's been ground down to 3" mains anymore?

Nope, because then you're stuck dealing with thrust bearing issues. Why bother when new cranks aren't all that expensive?

[Formulajones]

Originally Posted by hobbygto65

I take it nobody uses a stock 455 crank that's been ground down to 3" mains anymore?

I used to do that, then weld the thrust and seal surfaces and machine to size, back before aftermarket cranks were a big thing for Pontiacs.

Haven't had to do that in more than 20 years. With all the new cranks offered on the market these days that come in about anything you want it's not worth the effort anymore.