Help with a 58 300GH Hydra Matic retrofit

[wamantqs]

Guys or Gals, I'm looking to replace my original 4 on the floor with a 300 GH HydraMatic (this is what is spec'd as original for this model). First problem; finding one to retro into my 58 GMC 150. My real question is; I am very new to the world and grew up a Ford guy; please don't chuck anything at me. I've absolutely fallen in love with the 55-57 & 58/59 Chevy/GMC version trucks. The style and lines are incredible. I just found my baby and am slowly making a few basic changes as my wife wants to enjoy driving it also. I'm going to foster her "want" because it's a surprise that she enjoys the truck so much. I need help finding good places to find NOS and used parts for the truck; can someone point me in a direction that I might find a useable 300GH HydraMatic that I can drop into this puppy? Any help is certainly appreciated. Thanks, Mike P.S. - If any of you thinks I'm making a mistake in taking out the 4 speed, please do not hesitate to give me your opinion. I'm always up for well intentioned criticism.

[G&R's57GMC]

I have one in my '56 GMC "Cameo". Naner, naner, naner !

[OrrieG]

from what I have seen here hydros are expensive to buy and rebuild. Newer autos will give you a modern trans with overdrive and parts availability should you need it. You did not saw what engine you have (or want to use), but the search function will turn up lots of threads on how to adapt new trans to old six. V8 is a bolt on. Glen, play nice, he might get the wrong idea about us 4wd guys!

[G&R's57GMC]

Aw gee OrrieG I was just funin' with him.

[1project2many]

I have had two different versions of this trans. The 3/4 and 1 ton trucks have different gear ratios than the 1/2 ton pickups. As an experience. They're different from what we're used to today. The hydraulic coupling slips more when starting from a standstill and when driving, the shifts weren't as nice, and there's no park position. Also, they weigh as much as a second engine. If I wanted to go "all original" I wouldn't hesitate to use one but for the simple goal of installing an automatic to make the vehicle easier to drive I'd choose a 2004R transmission with lockup torque converter over the original Hydramatic. With either swap you'll need to make changes to crossmember, shift linkage, floor plate, and possibly exhaust but with the newer transmission you'll have less trouble obtaining parts from donor vehicles to modify and you'll find more aftermarket parts available if you need them. And, your local transmission guy won't hide under the table in the break room if you have to come in for repairs.

[agnes the dog]

I bought a set of wheels a couple weeks ago off of a guy who claims to have an original '58 Chevy truck automatic transmission. After I left his house, he remembered that he had it and sent me a text. He wants to sell it. I didn't need it, but told him I would pass the info if I ran into anyone. I still have his number. If you want to contact him, send me a message and I'll give you his phone number. He lives in central Indiana.

[Russell Ashley]

That original Hydramatic shifter that came on these trucks looks really neat in my opinion, but if I were converting my truck to automatic I wouldn't even consider trying to find one and the tranny to go along with it. I would take 1P2M's advice in a previous post and find a more modern tranny that has a Park and also an actual torque converter.
Although not a biggie, and someone correct me if I'm wrong on this, but I don't think any of the Hydramatic trannys ever came with a remote filler tube like newer cars have. Both of the one's that I've had had a short dipstick that was under a plug in the floor beside the hump and you had to lift the mat and remove the plug to check or add fluid to the tranny. Not something you had to do often but a nuisance when you did. Maybe this was changed in later models as my newest one was a 51 Pontiac.

[wamantqs]

Hey Guys, Geez, I really appreciate the help and direction with this situation with wanting to stick a HydraMatic in my truck. I thought I should stay true to the truck and go through the pains of finding the right tranny, etc.. I thought most of you would castrate me (excuse the strong language but that seems to happen every once in awhile around these parts) if I even suggested putting something more contemporary in the truck. I truly appreciate you guys sticking my nose in the right direction on this; I'm changing 180 and start my search for something along what's been suggested so far. Again, THANKS!
Regards, Mike

[1project2many]

Although not a biggie, and someone correct me if I'm wrong on this, but I don't think any of the Hydramatic trannys ever came with a remote filler tube like newer cars have. Both of the one's that I've had had a short dipstick that was under a plug in the floor beside the hump and you had to lift the mat and remove the plug to check or add fluid to the tranny.

I've never seen a remote check / fill point but I wonder what (if anything) might have been done differently in a step-van chassis.