im yankin my dads 300, ive juggled around a 408 stroker, but it will cost wayyy too much for what im gonna use it for. My question is; do i keep my c6 from my 302 or do i yank that 3spdOD that came in the light duty f150's? (aluminum case, the name/brand escapes me)


disregard this one, my computer screwed up and double posted.

 

It depends on what you want to do with it. I know that's the standard answer, but it is an important one with these two transmissions.

The C6 is tough, but it will drain on your horsepower and fuel economy a bit.

The 3spdOD, which is an SROD made by Tremec, is a light duty transmission, but the overdrive is awesome for long distance trips and gas mileage. They're also kinda rare.


So, if you are looking to really get out there and mud bog and drive this thing tooth and nail, the C6 will be your friend. However, if you don't abuse it, do light off roading, and travel long distances, the SROD is going to be right up your alley. First gear is also lower than the first gear in the C6, so that helps too.

I have the SROD and it works great for me off-road since I'm more of a destination finder for camping and backpacking and travel long distances on the interstate before I hit the dirt. I love it. But I know my limitations and know I can't abuse it.






That aside, drive the 300 for a little while. You may learn to love it. I wanted to pull mine as soon as I got it for a v8, but now I wouldn't trade it for anything. It's indestructible...and I can get 18 - 20mpg on the interstate.

 

i want good economy for city driving AND highway driving. I found a gear vendors over/under so i have an extra set for what i need... BUT heres the catch... my truck is going to get a complete drivetrain swap. im putting the 300 in place of a tired 302, mabe a manual (np435,zf5,SROD or keep the c6 but rebuild it), the gear vendors and a 4.11/5.38 rear gear. I looked at novak conversions and for me with the .70 overdrive of the SROD and the .78 overdrive of the gear vendors with a 5.38 ratio, i get theoretically a 2.9 ratio without facotring in the 32" tires. havin my cake and eating it too!

(cant drive the 300 w/ just a swap, 3.27 rear gears are really dumb getting off the line)

-this will be a daily driver
-this will pull a mountain if it has to
-I'm planning on building this 300, LOTS of torque where it needs it.

wow, i think ive answered my question. im gonna go buy a 5.38 gearset!

 

With the .71 and the .78 combined, it's like having an overdrive of 0.55.

At 65mph on the interstate, 32" tires, and a 5.38 rear, you're looking at around 2000 RPMs. Not too bad. Especially since when you gear down, those 5.38s will, like you said, pull over a mountain (and then drag it away) with that 300.

Keep in mind though that with that much overdrive, you'll want to baby the throttle at higher speeds. Overdrive gears are generally much weaker and are only for cruising.
Another thing to keep in mind, especially if you've had the 302 before, is the redline for the 300 is much lower. They peak out in power around 3000 RPMs and redline around 4500.


That sounds like an awesome project! Have fun. Put some EFI exhaust manifolds (if its carb'd) on that 300 and it'll really breath a lot better on the highway. I couldn't believe the difference.

 

yea im putting a 4bbl on it, efi manifolds with dual exhaust IF i dont lose low end wich i might, maybe a cam i have to see what this thing'l do just w/ efi manifolds

do you know if the GV double overdrive puts extra strain on the transmissions gears?

 

Any overdrive puts extra strain on transmission gears, which is why you're always recommended against towing in it. Then if you add overdrive to overdrive, you're doing even more strain.

However, keep in mind that at the point you are in overdrive, and you have your GV in overdrive, you are probably going to be doing highway speeds around 60 - 80mph. Unless you're towing, you're not exactly going to be romping on it and slamming the gas petal around. You're going to be just cruising, which should be fine. There'll be extra strain, but your engine isn't putting out that much torque at that time.

Another question for you as far as the SROD 4spdOD goes, do you have 4 or 2 wheel drive?

 

i was thinking about it all day in school and it occured to me; the trannys are all 4wd! (i have 2wd) so $150 later and a trip to pick n pull i should come out with a transmission. How hard would a hydraulic clutch be (i know its everywhere but im typing this atm) for like a ZF to be retrofitted on the truck?

 

Oh, yeah, the 4wd and 2wd trannies are different.

As for a ZF, best of luck on finding one. Fortunately, 2WD ones are not nearly as sought after, so it should be easier.

Here is a link to a long discussion about converting from mechanical to hydraulic clutch. It starts a page in or so:

Tranny confusion - FSB Forums

This guy also has a step by step photo gallery of his conversion:

1983 Ford Bronco Hydraulic Clutch pictures, videos, and sounds | SuperMotors.net



There is a lot of work involved, which is why I haven't done it yet and still have the SROD for my overdrive. Good luck!

 

sweet, thanks man youve been alot of help

 

No problem. Glad I could help.

If you decide to do the swap, keep us updated with pics!

 

well i got a reply from the GearVendors rep, Jeff Kubinza (i think thats his name) and it would be a grand total of $900 for a freakin tailshaft swap! DANG! with a $250 credit after they recieve my old tailshaft. Well it looks like im gonna have to keep the c6 for now, upgrade later to a manual. dang

 

If you're planning on possibly swapping for a ZF, why would you need the GearVendors? I've never really heard of anyone putting one in a manual anyway.
Consider yourself lucky though, the GV for the C6 is around $2500 if I remember right.

 

I was thinking of putting in that 5.38, so i can get going around town easier than usual (3.27 arent that fun getting up to 45 mph w/ 302)

added cruising ability goin over to lets say a 30 mile trip to fernley, ive concluded w/ the gear vendors i can have like a 3.09 with the ZF-5 and the GV backed with the 5.38

 

IMO an automatic has no place behind a 300 six, they just suck the power right down. I would not buy a 300 powered Ford truck unless it has a manual tranny behind it. I recently did a ZF swap into my 96 F150 after I broke the M5OD. The gearing is near perfect, it has a nice deep 5.72 first gear and a .76 overdrive gear. The truck rolls down the interstate with the same ease as it did when it had the Mazda tranny, mind you this truck has 2.73 gears in it. It actually yanks my 20 foot car trailer around fairly easily now, before I had to burn the clutch to get the thing moving! The ZF is a direct bolt in swap from the M5OD, all the parts will interchange with out issue. I am not sure how easily it will swap into an older truck though... as far as parts interchangeability (trans mount, slave cylinder, etc). With a little research it can be done I am fully sure. This winter when I do the 4wd conversion on my 96, I plan to dump the 2.73s for 3.55s. The ZF to look for will come out of a late 80s to 90s F250 or F350 with the 351w. They are said to be pretty tough, mine is holding up okay... I don't think they can take what the old NP435s, T18s and T19s held up to though. It's about the toughest overdrive manual tranny you can get.