318 Bellhousing

[Rifleshooter]

Hey guys. I have a 318 that I plan to build and pair with an A833od transmission. I already have both of them. I've noticed there's several different bellhousings out there for small block mopar in general. My trans has the 5.125 inch diameter bearing retainer and I was wondering what types of bellhousing are compatible for both this trans and also my F body without having to do too much fabricating to make it all work. Thanks in advance.

 

[4speedjim]

I think anything 75 up ie; OD has the big bearing retainer. Best bet is to find a 318 OD truck bell. Very few car v8 ODs. There is not enough room on most the older bells to safely open the case over 5". Specially over 300 HP in an aluminum bell. And you'll need a 130t 10.5 or smaller PP.

 

[Rifleshooter]

I found one that has the cast number of 3743859. Would this be one that would work?

 

[4speedjim]

Theres a site with every bell Chrysler installed with the part #s. Ill see if I can find it for you. That will answer all your questions much better than I can off the top of my head.

 

[Rifleshooter]

Well I've been on 2 different sites that show the casting numbers and such and one says that the 3743859 number is usable on f bodies and the other one doesn't so I figured I'd ask here.

 

[4speedjim]

Casting Numbers: Mopar Transmission Bellhousing Casting Numbers 1960-1981
I didn't look for your application, but will. I just wanted to get this to you first.

 

[Rifleshooter]

This site says it's for a 10.5 or 11 in clutch for an a833 and for an E body

 

[Rifleshooter]

As comoaned to this site which gives more precise specs
Brewer's Performance - Mopar A833 4-Speed Transmission and Component Specialists

 

[4speedjim]

Here is 3 I think are OD bearing holder bells 3893728,,,, 3743645,,, 3743857,,, 3893729 are the ones that should all be OD, 5.125 bearing retainer bells. The others I'm not sure have the room to bore that large a hole. And Id assume the Iron ones have a bit more room (thinner walls than alum. That is only an assumption though.

 

[4speedjim]

Oh ya, Brewers is a great place for info and parts. Any post 74 or 75 bell will be 5.125 and OD. *Except the truck np435 which is obviously wrong when you see the trans pattern on the back of the bell. It mounts horizontal instead of vertical like the 833.

 

[4speedjim]

Some bells have enough material to bore the back of the bell for the big retainer. I wonder if its possible to use a smaller, like 4.80 (rare) retainer and bell on an OD. I doubt it, but thought Id throw it out there. Warning!! I'm not a trans mech, or mech by trade. I am also putting an OD in my "Doba with a BB or Magnum. So I know a little...VERY little. But maybe you can turn the 5.125" down a little nd bore the bell a little and come up with a happy medium around 5" even?

 

[Rifleshooter]

I did a little more homework on that 3748359 bell and it has the 5.127 retainer hole and supposedly fits the f body so I bought it, now we wait to see for sure haha.

 

[AJ/FormS]

Fingers crossed! for ya

Hey RS, you know those ratios are quite far apart right?
3.09-1.67-1.00-.73 with splits of 54-.60- and .73od
The point is, that when building your teener, it won't take much of a mismatch in parts to throw the teener into a dog area in the powerband, especially on the 1-2 shift.
For the factory engine with plenty of torque right off idle,and a low redline, this wasn't a big deal. For example; the factory teener was typically shifted at say 3500rpm, the the Rs drop to 1890, and the factory teener can pull that easy enough. Even if you buzzed her up to say 4800, .54 of that is 2600, and the teener easily pulls that too. But think about that. At 4800 the factory teener is tapped out, and going into second at 2600, there is not a lot of power there.

This is made worse with a cam that peaks up near 5000, and especially with a low-compression engine. So I just wanted to be sure you were aware of this conundrum.

I ran this A833od behind a factory 1973 low-compression,not-tired 318, and with 4.30s it wasn't too bad, cuz the 1-2 shift came real early.(30mph@5000Rpm, with the Rs dropping to 2700, and second was good to 56mph). I also ran it with 3.55s, to get the hiway Rs down. But that was, I wanna say terrible for performance. I ended up installing a GVOD, putting the 4.30s back in, and running the GV as a splitter. Badaboom! that was sweet.

This od trans works pretty good the way the factory used it, but I pulled mine out about a dozen years ago. I like the 3.09-1.92-1.40-1.00 box much better. The splits are much tighter for any SBM, and the low first gear would allow you to run a 2.94 or 3.23 behind a hi-compression 318 and that would keep the hiway Rs down, and fuel economy up.
The splits in that box are .62-.73-.72 and a bonus, you can BAM! it into 4th, which would break the od gear KaBoom! I blew two of those up,one with the 318, and one with my 360. And guess what I discovered. There are at least two different Mopar A833od ratio sets, and the only common gears are the low-gear,lol. So now I have two broken-od gear boxes, plus the one still working souped-up box, and one for a spare. Hyup, the things you learn in HotRodding.Ain't it grand!

 

[Rifleshooter]

I had considered everything you mentioned. And my build list should give me all around better torque and power across the charts. I don't plan on going with a massive cam as I do still want it to be good at low rpms like what you said about the shift points. So no disrespect to you AJ and I'm not saying "I know better than you" like an idiot but I have taken that all into consideration and I appreciate the concern. Thank you

 

[AJ/FormS]

No disrespect taken, I'm just a guy trying to help.
Happy HotRodding,