Maximum bore on 383

-
440 Mike

440 Mike

Well-Known Member
Joined
Jul 18, 2016
Messages
359
Reaction score
169
Location
Minnesota
I'm tearing down a 383 with hopes of rebuilding it. First problem is someone has had it apart in the past. It's a stock 4.25 bore but someone used a ridge reamer, well tried to use one anyway. Lots of material removed, so my question is what is the largest over bore that a 383 can go? I will have it sonic checked but would like to know what the possibilities are.
 
I've read several articles that have said the 400 was a bored out 383. I don't know if that has any basis in fact or not. If so, that's a .092" over bore. That's a heavy cut. I just "don't know". Best bet is, if you want to be sure, have it sonic tested.
 
Have it sonic tested.
The typical Mopar BB ends up with a cylinder or two that’s core shifted pretty bad....... and that one ends up determining how big you can go.

Unless something is pretty far off, .060 should be safe, but I’d prefer a sonic test before doing it, especially if I’m looking to stroke it, and/or make some pretty good power with it.

There’s some pretty good general block info on the 440Source site.
 
PRH said:
The typical Mopar BB ends up with a cylinder or two that’s core shifted pretty bad....... and that one ends up determining how big you can go.
Click to expand...

Is it possible to shift the vertical axis of the boring bar towards the thickest side of that cylinder?
 
DrCharles said:
Is it possible to shift the vertical axis of the boring bar towards the thickest side of that cylinder?
Click to expand...

Sure, they can bore the cylinder sideways if you want. I've seen people move them around for one reason or another.
 
RustyRatRod said:
Sure, they can bore the cylinder sideways if you want. I've seen people move them around for one reason or another.
Click to expand...


That's interesting because as I mentioned earlier someone did some damage with a ridge reamer. It did not remove material evenly as the ridge is gone on part of the bore, while some remains on the other side.
 
440 Mike said:
That's interesting because as I mentioned earlier someone did some damage with a ridge reamer. It did not remove material evenly as the ridge is gone on part of the bore, while some remains on the other side.
Click to expand...

I wouldn't sweat that at all.
 
I’ve had a couple that were .060 that ran great with no problems. Any more than that I would have it checked for thickness.
 
I have another question that came up during the tear down.

When removing the pistons/rods, one rod bolt popped out of place very easily. How serious is this? Am I looking at resizing the big ends?
 
RustyRatRod said:
I've read several articles that have said the 400 was a bored out 383. I don't know if that has any basis in fact or not. If so, that's a .092" over bore. That's a heavy cut. I just "don't know". Best bet is, if you want to be sure, have it sonic tested.
Click to expand...

I was under the impression the 400 was a "siamesed" block like the Chev 400.
 
440 Mike said:
I have another question that came up during the tear down.

When removing the pistons/rods, one rod bolt popped out of place very easily. How serious is this? Am I looking at resizing the big ends?
Click to expand...
Get some ARP rod bolts, then resize at the machine shop
 
You must log in or register to reply here.
-

Back
Top