What is the bigest crank you can get in a low deck 383 block ? with little to no work with grinding ? 4.25 - 4.50 1965-71 block thanks

I don't think you can go more than 4.25 on a low deck.

I run a 4.25 stroke in my 383, A lot of clearance work for the rod swing.

I see the biggest problem is the rod getting to short on 4.25 and bigger crank, to short a deck height on a 383-400 @ 998 vs 10.72 for a 440.

I had 4.500 crank and 6.535 BBC rods at one time, for a 400 block. Pistons were 1.190 flattops, very light.
Crank had center counterweights, all the counterweights were cut back in their center areas for clearance at BDC.
It had some Mallory metal in it, but I never did a final balance.
I don't know how different a 383 block is in the crankbox area, compared to a 400.

It depends on which size rod journals you have on the crankshaft, I have one 400 stroker motor with 4.300 stroke with BB Chevy rod sizes on the rod journals, almost no grinding needed on the block other than the stock oil pump pickup boss.
Years ago I bought a 1959 383 stroker motor that was suppose to have a 413 crank with welded stroke to make it 1/2 stroker (stroked to 4.250) with the stock 383 rods and Jahns stroker flat top pistons. I was told it was 454 C.I. with the stock early heads and it had a old Isky 505T solid lifter flat tappet camshaft, I thought it ran good in my 1960 Dodge Phoenix weighing 4160 Lbs. without me in it, it ran. Best ET was around 12.70 at 105 MPH on a set of J.C.Penney 700x14 seven inch wide cheater slicks with a set stock 3:73 gears in open non posi rear end.
On your deal if you want to make it big you could go with a custom rod and have the crank journals ground to 2.00 size to get between 4.375 and 4.500 stroke and use a custom made real long aluminum or steel rod
The smaller Honda rod journal sizes are used in a lot of high end all out builds, but they have a limited life span due to the HP those usually motor make, 2000++++

4.25 in a BBC 9.800 is very popular. so no problem there. 4.375 is probably doable with little effort. 2.200 journal.

Thanks guy, A lot of people building #383 blocks, going #65 over finished bore to get the cubes + stoker crank

Mopar guys are weird, all the other makes are wanting taller blocks to handle the big stroke cranks while we do our darmness to go shorter! Back in the 80s a good friend had a Ford 429 Shotgun pushed out to 588 cubes, 4.3/4 crank and 4.7/16 bore built by Jack Roush. Pistons came up out of deck and had 5/16 aluminum spacers between head and block, very short piston-rod. Eventually the angle was to much and a rod came out, Made 830 hp (1982) with similar deck height of a 383. Slide that 383 to the side and use a high deck block.

Depending on what your goals are, etc.
Using a 4.250" stroke crank with 2.200" BBC 6.535" long steel rods is pretty easy, " with little to no work with grinding"
Here is a picture of the tiny grind on the oil pickup casting area (used 1/2 NPT pick-up).
Depending which 1/2 NPT pickup tube you use, the base near the block may need a little grind also.

Having the crank shop reduce the counterweight dia, and putting a bevel on the counterweight edges does the trick.

Who are the machinists that think a larger overbore (for minimally more cubic inches) is more important than thicker cylinder bores?!

WE know #65 over is one and dune as for as a stock 383 block and people chose that

Why .065 over? At .060 there’s a ton of ring choices (bbc) or .070 = stock 440 bore.

I talk to alot of people , and they are looking for #65 over, Im like you why not #60 over if you have to go that far, thanks on the crank photos, good point !

The stock 383 bore is the same as the 426 bores, 4.250. Boring it .065 will make it 4.315, why do that
I've built a bunch of RB and 426 Hemi at either 4.310 or 4.320 bore sizes when needed, never thought of trying to find or have 4.315 pistons made and use 4.320 rings on them, why are you wanting to do this?

People are crazy, it is not for me, i see it all the time, i think people are chevy/ford nut's looking for more power/ cube's that is my guess .