I see Passion does an OD HEMI 833 conversion. Has anyone on here done it, Any pros, Cons? Not wanting to drop the coin for a 5 speed for my Demon, and honestly not even remotely interested in cutting it up to make one fit either.

Jamie quoted me 2800 ish for the gearset and parts. I can swallow that easier than buying his drop in tranny.

It has been a long time since I did it, but the main issue is the input bearing size. On the OD case they increased the size of the front bearing, mainly because power in OD is always going through the cluster shaft. In a regular 4 speed they lock the input shaft to the output shaft for 4th gear so the gears are just turning in the oil, no power going through them, main reason they last so good. So if they are putting the OD gears and using the small bearing diameter, in a Hemi trans, not sure how it would hold up. Used too be a lot of the dodge truck OD transmissions 23 spline were available in junk yards so we had the hole in the bell housing machined to fit the bigger OD bearing housing and it was a bolt in deal pretty much. Any decent machinist can bore the bellhousings. So if you are using the Hemi spline then one of their kits might be the way to go. But I would defiantly ask them about how the input bearing holds up, Chrysler engineers made it bigger for a reason in the OD units.

Ive done all of the conversions out there, the Passon OD hemi gearset, a Tremec and a gear vendor OD unit. The Gear Vendor OD unit is hands down the best. You don’t have the super wide ratio like in Passon’s set or the super low 1st gear like in the Tremec. All my customers love the gear vendors.

GV is the smallest change @ 77.8% recovery, but it can be switched in & out to create intermediate ratios (1, 1½, 2, 2½, etc.).

Last year I installed a Passon Hemi overdrive in my 70 RoadRunner..
Jamie designed/tooled a new set of OD gears, much better than using an old set of gears out of another transmission.
Basically its ratio are similar to the torqueflite but with an added overdrive.
For my application, just cruising to neighboring car shows, but on the freeway @65 MPH with 3.91 gears the RPMs dropped down about 20% to 2600....

If one is not racing, I strongly recommend going this way...

Just my $0.02...

why do they love the gear vendors? it does have the least amount of drop for the od. i get the very liitle to no cutting. are your customers auto guys or 4spd guys?

GV can take 3,000 hp

Both of the ones that are running at the present are 3.54 Dana rear and hemi 4 speed. One guy has never had a stick car but loves the way the hemi 833 shifts and loves the rpm drop in OD. The other guy had a Tremec we installed years ago. It has always been trouble. It would not shift good at high rpm, has a terrible first gear ratio, and is noisy. He sent it off twice to have it worked on to shift better with no luck. He loves this new GV od because of the first gear ratio, final drive, it’s quite and you can shift it at high rpm. What’s not to like. I’d love to sell his POS Tremec and bell housing to get it out of my shop.

I've got two GV ODs.One is behind a 390 small block, the other behind a 512 BB. Couldn't be happier.

I have one in my RR, I like it for just cruising, but it feels kind of stiff and I don't think it would shift quick enough for racing. It's really nice for a big torque engine, as you can just stick it in OD and lug around. And on the Interstate I run with the fast cars. I would say the biggest benefit is the fact that it just bolts in with all of the stock parts and hardware, you don't have to try and figure out what part came from what other car brand if you need something.

I'm guessing that's why some of the drag and drive unlimited racers carry a spare .

Nothing never breaks.

What about a 8HP70 conversion? I would choose 8 speeds including OD over a 3 speed with a GV's. These where put behind the hellcats so they will just about handle anything you put in front of it. link

This is another option.

The GV gives you 6 gears. Do you really need more behind a 500+ inch stroker? That 8 speed will be big $$$ by itself and then it needs a $tand alone controller that I'm not sure even exists and if it does, is it readily available.

I would use the GV kit for the short tail motorhome trans to keep the overall trans length and driveline angle reasonable.

I think they also make a shorty kit that uses the married 4x4 output shaft to make it a really compact installation.

Kevin

Another GV advantage I can think of is the use of an intermediate gear (in a 727: 2½) with a street axle ratio to assure reaching max RPM in the traps, where 2nd gear is way too short and high gear would be not only too tall but too great an RPM drop. 727: 2½ shift to 3 only loses 11%, versus std. 727 2-3 shift loses 31%.

I've never met anyone with a GV who actually splits the gears. They all did it a few times when it was a new toy but then it went right back to 3 speeds plus OD.

Of course, you only do this when you need it (as I described), it's not a toy.