Questions about 383

[Rusty Nail]

A 383 is merely a 0.30 over 350 block clearanced internally to accept the wider swing of a 400 crank. Same rods?, pistons and everything else. Visually impossible to determine. The ONLY way that I am aware of to be 100% sure, is to disassemble it far enough to read the number on the crank.
That will actually require quite a bit of disassembly....a lot.
I'd just tell em it's a 350.

(And even though those numbers are NOT actual that are wildly accepted as fact.)

 

[Skweegle89]

Or the burn out thing. Easiest way to tell.


Sent from an old rotary telephone.

 

[Don5]

Driver side dipstick is pre 80s so yes 2 piece rear seal. The 010 is actually on the driver side behind the head. Usually covered in years of grime and requires some cleanup.

OOPS. My bad...

 

[Tony778]

Haha let me get the rear main replaced, and I'll see what I can do...

 

[Rusty Nail]

Well Tony, the crankshaft casting number will be stamped into one if the counterweights towards the front of the crank = oil pan removal = engine removal ?
Quite a bit of disassembly is accurate.
Basically a 383's additional cubes result from the pistons traveling further down the bore. The result is increased or advanced thrust wear.

Best wishes.


*or you could just do the burnout thing. Be sure to take a video, that's all.

 

[PrairieDrifter]

A 400 crankshaft dampner is designed differently and looks different as well as it is balanced differently. That being said im not positive if you would still use the 400 dampner even on a 383 which is a stroked out 350, being its a 400 crank I would imagine that they would have to use a 400 crank dampner. Only other way is to take the pan off, you should be able to see the parts of the block that have been stroked to fit the rods and crank, in other words ground down right under the cylinder walls, it should be pretty easy to tell that way. Im pretty positive you'll be able to tell by the dampner though.

Im not sure how easy pan removal is on a 2wd but a 4wd it isn't that bad.

 

[Tony778]

Thanks for all the help and input guys. I found a decent how-to for a 2pc rear main on a 350, that should get me through (after I finish working on the fiancé's friends Buick...).

After this a few carb/timing tweaks, be on the lookout for 16.5" wide black marks around the Winston Salem area

 

[firebane]

Thanks for all the help and input guys. I found a decent how-to for a 2pc rear main on a 350, that should get me through (after I finish working on the fiancé's friends Buick...).

After this a few carb/timing tweaks, be on the lookout for 16.5" wide black marks around the Winston Salem area

2 piece is pretty easy. 2wd will be a bit more challenging as its not so easy to drop the pan. But once the pan is out the rest is pretty simple.

I've just recently done it as a few others have so if you have any questions.. ask.

 

[brianhannon]

Look at the harmonic balancer. The 400 crank balancer has a large cutout in the side (an indent sort of thing) and a 350 balancer just has the small tick mark for timing. Unless the engine was built using internal balancing, you should have a 400 balancer. I know more and more people are doing the internally balanced route, but if you don't have a 400 balancer, you'll have to pull the pan to make sure. Hope that helps!

 

[Tony778]

Alright everyone, got the pan off and snapped some pics. Can anyone tell from these pics what crank this is, 350 or 400??

 

[Tony778]

...

 

[PrairieDrifter]

Take a picture of the bottom of a single cylinder wall, and also take one of the balancer

 

[firebane]

I can't see any clearencing done but I can say you have a 4 bolt main.

 

[Quadrajet Power]

A couple have mentioned this, but the 383 is usually externally balanced, so the flex plate and the balancer will weighted and balanced to the crank.

My old 82 box has 383 I was told, but wasn't sure. I could tell by the balancer. Since you have pan off and are in there anyway, look at the flex plate and see if it has weights on it.

 

[Tony778]

I hope I'm wrong guys, but from everything I'm seeing, there is no proof this is a 383.