So you guys that have done the c4 to flatty swap how happy are you with it and how was it to do? I went on a long trip last weekend about 130 miles each way on turnpike and the old 2 speed ford o matic just wasnt happy howling the whole way. Worst part was not being able to keep up with my buddies ,they thankfully slowed down for me, but I know they wanted to tear it up a little . what am i in for since I have never done this before thanks guys oh by the way I have a stock rear and my flatty is a pretty stock 52 and 6volt
C4 won't help with top speed because final gear ratio is 1 to 1. Flathead engines don't have a lot of horsepower. Any automatic trans will sap what little power you do have. Have you considered a T5 5-speed swap? It will put the fun back in driving and will also give you a nice overdrive 5th gear. Clutch pedals aren't hard to find. Just something to be considered. Best of luck...jack
Thanks been hearing alot about the t5 swap maybe what I nee to check into. can I keep the original rearend or do i need to change that too
I like my c4 running 255 mercury with 2.78 gears 205/70/15 tires. 2000 rpms 55 mpg 2500 should do 70mph. I shift mine manualy most of time never miss a shift.
As stated unless you went to something with less than 1:1 in top gear your top speed cruising would be no different. If you do not mind shifting a T5 would be an excellent choice. Assuming it is still original, I believe rear end ratios for Ford-O equipped cars were 3.31 standard with 3.54 optional which should be ball park where you want to be depending on tire diameter, engine HP, and how fast you want to cruise. You might verify your rear end ratio, ratios were available as low as 4.27 and if someone swapped something lower sometime in your car's history your cruising ability would be toast.
I put a c4 behind my flattie and for some reason I kept breaking parts(Not common) I soon switched to T5 and Love it. It was worth all the hassle of putting an extra pedal in. But I happen to like rowing the gears.
Yea seems like t 5 would be it. Maybe Ill just wait till something breaks and then get a plan together . The car runs great now just wanted to get some options together for when the time comes like to be prepared thanks guys
Now is a good time to research and start finding parts as they come available. Nothing worse than breaking down and then paying high prices for parts cause you feel the need to get it on the road fast. Plus spreading out the cost makes it easier on the back pocket, unless your one of those guys with money!
I put a Flat-o-matic behind mine in a '53 merc. I keep ripping the studs off the torque converter and it makes this awful sounding knocking noise when it happens. I've welded them back on 3 times now and it did it again the last time I drove it.... Everything is installed and set right, and my converter has the play in it its supposed to with the crank and all that. Needless to say I havent been real impressed with it. I'm pulling it back out.
I was cracking flex plates with the speedway kit for a C4 to Flathead. Cracked 3 then bought a Flat O matic adapter, the starter and flywheel were not cooperating. After pulling the trans 5 times in two months I did what I really wanted in the first place. 5 speeds and a third pedal. I ended up changing the entire floor structure, F1 steering box and column(which was the best thing I ever did to my A) I have read where many guys are happy with the C4 automatic though.
Everyone talks about how cheap a t-5 is but I have never really seen an actual price, a $100.00 $500.00 how much. I know different areas may be different but rough guess?
x2 on the s10 t5. the tailhousing is in the right spot for ya. if your making decent power your gonna want a world class t5, and then throw the s10 tailhousing on it for the better shifter location. i doubt youd need a world class behind a flatty though. check out the ultimate t5 tech thread. assloads of info on there
also ~ $200 seems to be a fair price for a t5. world class is a tad more. also if you look really hard, certain s10 t5's from 1993 models only are world class. so thatd be the trans to get. pretty hard to get ahold of though
I think I gave $250 for my s10 trans(the older ones like mine have mechanical speedo). Mine came with a Dwight Bond adapter. I bought a 10.5 clutch disc from speedway that has the right splines and used a hogs head bellhousing that I had. I went with a hydraulic master and a slave cylinder to actuate the clutch fork. I moved my clutch set up to the passenger side to open up room under the drivers floor, not much room under a channels A bone. I did a ton of reading so when I did the conversion it went really smooth. My Flathead now runs down the freeway at 80 just purring.
I have a c4 in my model a coupe with 50 flathead,8in.ford rearend.it does good on interstate but for lowend it kills it.wish i had a 5speed.
This is what a adapter kit looks like........they're quite simple really, & not expensive, just make sure you get the kit with the larger flywheel. I think it's got 164 teeth. Kit includes a starter end that fits a common 1970s -1990s Ford 12V starter. You have to grind a small knotch for it to fit. All done.................
Don't waste your time with a C4 and go with an AOD Ford auto so you can keep up with your buddies!! Kits are available.
The Flat-o-matic conversion will be coming out of my car very very soon. (hopefully tonight...) It does do well on the highway, but like others have said. Sucks down low. I will probably put it up for sale in the classifieds when I get it all apart. Adaptor, flex plate, converter, TCI trans, and the shifter. If you want to cruise, it works well.