Hello everyone, I have a 48 ford 5 window coupe W/ 350 Chev SB and a 400 turbo trans (that shifts firm and perfectly) and a Ford 9 " rear end 4: 10 . When driving on highway at 65 mph my rpm's are to high so I'd like to put an O/D trans behind the 350. I know people will say put a 700r4 in but I have access to a fresh strong ford AOD trans that has the throttle cable to carb linkage. Doe's anyone know if they make a kit that will bolt to the 350 SB and Ford Aod trans ? The trans is a early model Aod cause it fit the 351 windser / 351 Cleveland blocks. Thanks neil
Have you considered using a more highway friendly rear axle ratio? Much cheaper and easier to change the 9" third member than either engine or trans swap. What do you do with the car that requires a 4.10 rear end? Ray
If you want to use the AOD get a ford engine If you dont want to change the engine go with a 200r4 which is the same length as your 400. Or go the easiest way and change the rear gears for less than $200 to around the 3.25-3.50 ratio range.
Over on HotRodder.Com, is a guy with a 49/50 Chevrolet 4 door sedan (goes by tapkoote), has a journal posted there where he put a FORD motor into the 49/50 Chevrolet, and used a TH350 transmission. If they make an adapter to fit one way, it only makes sense they'd make one to go the other; or maybe the same adapter would work. He "was" a member here a few years back. Got himself "enemitized" with me when he accused me of selling him his POS 49/50 Chevrolet, and I've never even met the guy (????). Maybe check with him on the "photo journal forum" on HotRodders.Com. Why he did't just use a Ford trans, who knows? I am Butch/56sedandelivery.
I'd go with changing the third member to gears that were more road friendly and then just keeping the 4.11 stashed in case you want to go play at the drags. For most guys on here that is a swap that takes under an hour in the garage at home with no lift As the guys said you could swap in a Ford engine to match the trans cheaper and easier than you could adapt that trans to the Chev engine. That would be a one off machined out of a block of metal adapter that had a lot of hours of design in it plus a lot of hours of machine work. This is one of those times that the "I have it and want to use it" thing doesn't work well.
When I bought the car that's what rear end was in it and still the same. I drive it around town and sometimes want to travel on longer runs but I don't want the engine rpm to run high for a long time. I mean it's not that bad but when driving it you feel like it should shift one more time . Maybe I can get a used 9" unit that has a taller gear ratio. What do you think a good all around gear ratio would be ?
I don't know your tire size, but I'd guestimate at 65MPH your probably around 3200 to 3400RPM with a 28" tall tires and the 4.11:1 gears. If you swapped in a different pumpkin with say 3.50:1 gears your 65MPH RPM's would drop to about 2700 to 2900. With the new gears your car won't launch as hard as the 4.11:1 set, but it would still be acceptable. Drop to a 3.25:1 gear set and I'd imagine your highway cruise speed to be down around 2600RPM range. My suggestion build a small journal 327 and install a set of 4.30:1 gears. -Dave
Pondering it a bit I'd have to wonder why you want to run the 4.11 gears in the car? Is that what the rear came with, what you always wanted or what the cool guys down at the corner gas station said to run? Or ????? Here is a chart that is easy to play with even though it came from a Toyota Tacoma site. It lets you figure out the roll out of different tire sizes Plus what the tires will do with different gear ratios at certain rpm https://www.tacomaworld.com/tirecalc?tires=225-70r15-225-75r15 With the 28.29 inch tall tire and 4.11 gears the rpm would be 3173 at 65. Plug your tires in and see what you come up with. If anything it will help you figure out what you want for a final drive ratio be it with an OD trans or rear end gear change or even taller rear tires in the mix.
If you want to change the third member, one of the things you'll need to determine is the number of splines on the axles where they plug into the differential. Passenger cars usually have 28 splines, pickups, vans and hi-perf cars usually had 31 spines. One clue to that might be the wheel bolt pattern size. If you have 5 x 5 1/2", it's likely a truck or Bronco axle assembly. If 5 x 4 1/2" pattern, more likely, but not for certain, a car axle. The most common car ratio I have come across is 2.79/2.75, but they can range 3.25/3.50/3.70. Trucks/Vans more likely to be 3.25/3.50/3.70. Another possibility, depending on your bolt pattern, is an 8.8" axle assembly from an Explorer. They can be found with 3.27/3.55/3.73 and often are limited slip. Earlier Explorers has drum brakes but many/most are disc. If you go that route, I would recommend trying to find a 3.27. Good all around ratio. Ray
Good solution but for the '48 Ford has X member frame......Gear Vendors wouldn't fit .......unless the X member has been removed or heavily modified to accommodate the TH400. Really, for a transmission solution, the 2004R that was suggested by several others, would be the easiest in that regard. Ray
Thanks for the info Ray I will start looking for maybe a 3.00 to 3.25 ring and pinion set thanks neil
By the way Mr46chev I love the car and it came with that gear set in it. I have had to dump over 4K in the engine so far and the rear end is next. I will keep at til I get this baby just the way I want it neil