I’m looking at keeping my flathead as long as I can since she’s still running and it has the current the 3spd w/OD hooked to it however it needs some work. So the conundrum I am in do I get it rebuilt or do I swap it to something like a c4, c6, AOD or even something else. I’m not a speed demon and racer, I just want something reliable and can maintain normal highway speeds. Thanks for the suggestions
I'm a big fan of the BW 3 on the tree with OD, they're just seriously trick. If it were mine I'd rebuild it. The main problem with them is folks use the wrong oil. These transmissions want straight mineral oil, no hypoid additives that will eventually damage the br*** synchronizers. Before you discard it check out Van Pelt Sales, http://www.vanpeltsales.com/. Mac will have the parts you may need and will even rebuild your trans if you wish. That said, if you just want to go shiftless check out the Flat-O-Matic C4 adapter for flatheads.
thanks Tom! Yeah I’m torn between keeping the 3spd or going a different route. I actually have a 302 I’m slowly rebuilding in my garage to go in it maybe at some point but in no rush at all. Just wanted to rebuild a motor completely for the first time. that being said, is there any tips tricks or insider trading you’d have if I went with an auto trans for 53 with regards to having to modify more of the trans tunnel, mounts etc etc. thanks!
To my knowledge no mods are needed to the trans tunnel if you're wanting a C4 or C6. You may need to modify the trans crossmember. Since your car came with an OD trans and if you have the original rear end the ratio will be between 3.90:1 to 4.11:1. That means the flatty, or any other engine you swap in, will be spun up pretty good at highway speeds. To tame it you'd need to swap in an axle with a numerically lower ratio like 3.20:1 or so. Read that more work and expense. You may find it more wallet friendly to rebuild your OD trans. They're actually very simple transmissions but if you're inexperienced in rebuilding manual transmissions it's probably best to have a shop do it. There is a reprint of the official Borg Warner manual available, just google "The Overdrive" to find it.
ok great information right there. I might just do like you said and just get the BG 3 spd operational and just have fun for a while before hitting off more than I can chew at the moment.
From what I’ve read C4’s are starting to get harder to find so if it’s a non OD your looking for I’d start watching. C6’s take a lot of HP like a Turbo 400 and really not needed for smaller engine street applications. I was looking to up grade to a 3 speed automatic and tried to make it as simple as possible. I also felt a new more modern rear end with better brakes was a good idea. I choose NOT to use an OD and went to a 2.70’s rear gear in the 8.8 style and couldn’t be happier. It’s just fine in traffic and 2200 at 65 mph. There are many options for the Ford 302. Just make sure you get all the correct parts hopefully from someone changing to a 5-6 speed. Good luck
The adapter kit to bolt up a Flat Head to an AOD or C4 is currently up to $950 then there is the issue of parasitic HP drag a C4 is about 35 HP the AOD is about 42 HP and the C6 as much as 60 HP that is a lot for the flat head it would make it a real dog. My '54 had the 223 Six and 3 speed O.D. rear end ratio is 4:10 which works just fine with the 302 & AOD 70 MPH is about 2200 RPM in O.D. If you are keeping the Flat Head Tom gave you the right advice.
Right on. However, Speedway offers an AOD adapter for about $478. It is what I used and works well. The stock 3.90 rear end (too low) caused a shifting problem so I used one of the Transgo valve kits (was $25) that cured the problem.
Did you mate it to the flathead or 302? I currently have the flathead running so I was just going to rock that until a later date. How much work went into putting the AOD in? Thanks!
We mated it to a flathead. No real issues, just grind a bit off where the starter mates to block, put in a trans cooler and make the center x-member a bolt-in. Took off the clutch pedal and used an auto-shift column. Had a plastic shop make a new shift dial which made linkage alignment a breeze. Search the threads and you will find photos of the switch.
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