another one was 4L block and crank, 3L rods and 5.0L pistons. Keeps 4L and gets you forged pistons provided you block can handle a 4" bore. Stroker 5.0L to 347cid run 3.4" stroke and 5.4" rods, the 4.0L has a 3.32" stroke and the 3.0L rods are 5.5315" so the rod ratio is decentat 1.67":1" where optimum is 1.7":1". Stock 4.0L is 1.73":1". The previously mentioned set up would be 2.07":1" which would be one hell of a screamer.

 

yeah it would, it would wind up real fast, but you would lose a decent amount of torque, some setups could sacrifice a bit though, depending on the application.

 

the destroke was meant to fit some cheap forged pistons, but the post i just entered I found a better way lol.

 

That would be a good way to it, never thought of that. what is the stock bore on a 4.0 again???

 

with the 3.0L rods and 5.0L pistons youd still be down the hole 0.06" tho...some tweaking and it would get close.

 

Thats deckable in most cases though

 

stock bore is on that link I posted...3.95" on a 4.0L

4" bore
3.32" stroke
6 cylinders
------------
250cid/4.1L

 

I think .050 would be pushing it on a 4.0, it would be worth a try though.

 

hell Id do it just to save the money on custom pistons...first time building one id rather be out $500 than $5000 when the thing blows up lol.

 

since weve completely derailed this thread I figure we might as well keep it going lol.
I did some more digging:
5.0L pistons use a 0.912" wrist pin. Guess what, the 3.0L also uses a 0.912" wrist pin. The 4.0L rod journal diameters are 2.1256". The 3.0L NON-Duratec rod journals are 2.1257".
That means the 3.0L rod will go right onto a 4.0L crank and the 5.0L piston will go right ontop of the 3.0L rod. I dont know how to find rod widths and what acceptable clearances are on them.

 

I had my 4.0L block sonic checked before boring it. The walls of these are actually quite thick! It would take 4" easy. Here's my quote from my other thread:

 

I know youve posted valve size somewhere but I cant find the thread I saw it in. What are the valve sizes on a 4.0L?

 

Man.. this thread has really taken the scenic route thru hill and dale of 4.0 tech talk. I asked a basic ?? back a month ago and it's still going! It's a little off track but HEY! This is what these forums are supposed to do, I guess. So, the old ??, Does anyone make a 4.0 carb intake?? and a new ??. If I replace my 4X4 AT with a 2X4 tranny, will the on board ECM recognize everything OK or will it be confused? Are there fixes for any glitches that may come up? 94 4.0 EB Explorer

 

noone makes a carb intake for a 4.0L. I dont know the answers to your other questions, someone else should tho.

 

As long as you replace the 4x4 a4ld with the 2x4 a4ld, youll be fine.