I am wanting to get a little more pep out of the 300 6Cyl that is in my 78 F150 4x4 flareside. I don't know if it is the performance of the engine itself that I'm having trouble with or if it is the gearing of the tranny and rear-end.

I don't know which tranny it has in it, but I can tell you this. It has the granny gear. I take off in second gear, shift into third at about 18-20mph, and if I really rev the rpm's I'll shift into 4th at about 35mph.

I'd like to get a little better performance out of the truck. Also it has absolutely no get up and go once you are in 4th gear. At 40-60 mph if you give it the gas like you are trying to pass or something it will slowly increase in speed. It's just not a peppy driver.

Is there any thing I can do about this??? I don't know if it is a transmission thing, the gearing in the rear end, or if it is a combination of a lot of things.

I've had the truck for a while, but have just recently decided to make it a lot nicer looker and driver. If I need to give info as to which transmission it has and which rear-end, I'll need some guidance as to how I find those things out. I'm sure there are numbers that tell me somewhere, but you'll have to guide me to where they are.

Thanks for the help.

Chad

 

Chad,
It sounds like you got too much gear. Look for a metal tag on your rear end. The number on that tag will tell you the ratio. My guess is you running a 4:10 rear end. They made a 3:00 that would suit you well for highway driving as long as your not doing any boat pulling. Performance parts are available for you 300 sixers. Be careful not to over carb your six. they have a bad tendency to wash out the rings. You've got a four speed which rids you of all sorts of problems associated with the 300 six. Is this a short or long bed? You said flareside, I think? Exhaust will help, alot, and I do mean header.
If your interested, ask. The six cylinder revs up better due to its in line design and can perform well under the right conditions.
KingFisher

 

I'll take a look at the tag on the rear end tonight and post those numbers tomorrow.

I'd really like to spruce up my truck. It is a 1978 short bed flareside 4x4. I'm having some body work done and it will look nice, but I want it to run nice. I don't do very much 4 wheeling so super low gears are not necessary. I don't want to loose the ability to 4 wheel, but for no more than I do it I need a daily driver. Also Gas mileage is killing me. That engine is really turning the rpms at 60mph.

I just found a web site: http://www.cliffordperformance.com/

I wish I had the money to really trick my truck out :-)

Check out the intro to that url. I want my truck to sound like that :-)

Thanks for the help.

Chad

 

[Quote]
>It sounds like you got too much gear. Look for a metal tag
>on your rear end. The number on that tag will tell you the
>ratio.

Below are the numbers from that tag. Can someone decipher this for me?

H82 - top left
7HB - top right
509 - bottom left
390B - bottom right

I've designated where the numbers were on the tag incase that makes a difference. Also they were pretty hard to read, so an "8" may really be a "B" and vica versa. Thanks for the help.

Chad

 

I answered your shadow post in the inliner forum. You've got a 5.09. I know this because I just checked mine last week. Next thing you'll be wondering is what's the spline count. Someone posted (in this forum) that they could identify the spline count from the tag info. I never got a reply from my previous post when I had my numbers up.

 

Thanks for the help.

I'd rather have a higher geared rear end, but since I have a 4x4 wouldn't I have to change out both rear ends?

Chad

 

 

what size tires are you running?

 

I've never heard of 5.09 being factory gears (not saying you are wrong, though.) That would give a rpm of around 3300 at 60 with 31 inch tires. Even 42" tires only bring you down to 2500 rpm at 60 mph.

I would imagine you would have no problem swapping someone with a V-8 and 3.5 gears for your set, they would be perfect for a set of 42-44" tires and a v-8.

Are you anywhere near NC?


G

 

I've had the truck for over 10 years. I've drove it when I was 16. Dad liked the gearing because there was just no way to drive it like a Hot Rod :-)

It has 31x10.50 tires. I don't have a tach, but the rpms you mention sound about right. No wonder my gas mileage is killing me!

The only thing I can figure is that someone used to have some pretty big tires on it, or they did a lot of rock crawling 4 wheel driving...or perhaps both.

So I will probably be looking to swap the rear-ends in it. The thing is I would need to swap both the front and the back...correct?

Someone told me about something called a "Switcher" or something like that. They said it hooked up between the driveshaft and the pumpkin. Made it have higher gears or something...anyone know about anything like this?

Would anyone out there be interested in a swap? I'm located in Southwest Missouri (Springfield, Joplin area).

Thanks for the help,

Chad

 

Advance Adaptors makes an item called the Ranger Torque Splitter. It is a Overdrive unit, and would indeed drop your RPM's considerably. I think it goes inbetween the engine and tranny, so you could use it in 4wd. Gear Vendors makes an overdrive of about 25%, it goes after your transfer case, so it would only work in 2wd. Both are pricey, you would have to drive a lot of miles to justify the swap on gas savings alone.

In answer to your axle question, yes you have to swap both front and rear gears to still operate in 4wd. You could swap just the back, but then could not engage 4wd without breaking something.


fordmando
70 F-100 400 C6
78 F-150 4x4 400 NP435
George Selby