slant gears help

-

75gold.uster

Well-Known Member
Joined
Feb 24, 2012
Messages
103
Reaction score
0
Location
california
i have been looking around to see what i need to make my slant a bit faster, and gears is what im looking at i have a 1975 gold duster and i dont know whats in there stock? basicly i just wantt to know exaltly what i need?thanks for the help guys i know i have been posting alot.
 
If I were a betting man, I'd bet you have 2.9sumpins in a 7.25 rear. If drag racing is your bag, I would jump a full ratio to see a real difference. I wouldn't waste my time going less than 3.91's. I've changed 1/4 to 1/2 ratio, and it's just too small of a change. Going in your case from say 2.9's, to 3.23's or 3.55's just isn't worth it.
 
You gotta know what you have first, see if you can find a tag on one of the housing cover bolts. It may be as low 2.45:1, but don't get ahead of yourself. Remember it will also change the overall drivability.
 
I am building a slant car now. It will have 4.30 gears when I am done.
 
If I were a betting man, I'd bet you have 2.9sumpins in a 7.25 rear. If drag racing is your bag, I would jump a full ratio to see a real difference. I wouldn't waste my time going less than 3.91's. I've changed 1/4 to 1/2 ratio, and it's just too small of a change. Going in your case from say 2.9's, to 3.23's or 3.55's just isn't worth it.

should i gett a whole new axle with bigger gears in it? or just replace the gears? its going to be a street driven car so what size u think would be good?
 
alright my gearing is somewhere between 2.45 to a 2.73 with 7 1/4 rear end. what am i goona need to hold my own with 5.0 engines? shall i gett a whole new bigger rear end or just up the gears? thanks alot for your help guys it means alot
 
Unfortunately, unless you get lucky and score an 8-3/4" rear, you will get an axle that requires a good bit of cash to set up gears. The 8.25" rear is a little easier to find, and generally cheaper, but you won't find one stock with much lower than 3.2 gears. Other than strength, you won't gain anything. As another poster mentioned, going low in gears will affect driveability. When I cobbed in the International rear with 4.27's it knocked my gas mileage down a bunch. The performance was so much better, I didn't care. If you switch gears, I wouldn't go higher than 3.91's. 4.30's would be my choice.
The 5.0 class is tricky. I could beat 5.0 Camaros easily, but a 5.0 Mustang is a different deal, much faster. With the shaved head, home porting, 2 bbl, and the low gears in a 2,700 pound car, it was still maybe a 15 second ride, or a little faster. Slants cost money to go fast. I won't try to talk you out of it, hey, I did it, twice in fact. If you are on a real budget, and speed is most important, a junkyard 360 and trans will save you a bunch of money.
 
Unfortunately, unless you get lucky and score an 8-3/4" rear, you will get an axle that requires a good bit of cash to set up gears. The 8.25" rear is a little easier to find, and generally cheaper, but you won't find one stock with much lower than 3.2 gears. Other than strength, you won't gain anything. As another poster mentioned, going low in gears will affect driveability. When I cobbed in the International rear with 4.27's it knocked my gas mileage down a bunch. The performance was so much better, I didn't care. If you switch gears, I wouldn't go higher than 3.91's. 4.30's would be my choice.
The 5.0 class is tricky. I could beat 5.0 Camaros easily, but a 5.0 Mustang is a different deal, much faster. With the shaved head, home porting, 2 bbl, and the low gears in a 2,700 pound car, it was still maybe a 15 second ride, or a little faster. Slants cost money to go fast. I won't try to talk you out of it, hey, I did it, twice in fact. If you are on a real budget, and speed is most important, a junkyard 360 and trans will save you a bunch of money.

thanks for the help cuda! sorry if im bugging you . when u say gas milegae went down, how much? i found a rear end from an international with the 4,27s. if i were to get it would i just have to swap the differnentials and be done with it? or do i still have to get inside it and change gears out? thanks!!
 
will this be a street car? or drag?

Street car. I am going to run a 4 speed overdrive. With the .73 overdrive gear, my final drive with the 4.30 will be 3.139 so it will be very streetable.

If I were you though, I would concentrate on getting the engine running in peak form first. It can easily become overwhelming if you try to look at it all at the same time. Work on one section at the time and take your time and you'll get it done.
 
Unfortunately, unless you get lucky and score an 8-3/4" rear, you will get an axle that requires a good bit of cash to set up gears. The 8.25" rear is a little easier to find, and generally cheaper, Slants cost money to go fast. I won't try to talk you out of it, hey, I did it, twice in fact. If you are on a real budget, and speed is most important, a junkyard 360 and trans will save you a bunch of money.

XS2

thanks for the help cuda! sorry if im bugging you . when u say gas milegae went down, how much?

first, if you are worried about gas mileage then you should not be looking at gears or major upgrades. secondly, if you are trying to holeshot 5.0 litre cars on the street, dont. third, if you dont have any real money to do the machining and upgrades that the slant needs to smoke the mustangs and the commodes , then you my friend are better off with a V8 that doesnt need a crapload of machine work and upgrades. this topic has been beat to death before. be prepared to pull the slant, and ready to spend some cash, you also need someone that is very knowledgable specifically with the 170,198,225 slant sixes or you are pissing your money away. not to sound like an ***, but these engines need special attention to run like nobodies business. there is great info all around FABO and some of these guys are making insane horsepower with them but its not cheap and not a matter of just bolting stuff on it. im not trying to talk you out of it, just making you aware that speed costs money, and the slant is no exception. with a great tune-up, set of headers,a good intake and some timing, that 302 torino would have left you in dust where my basically stock V8 would have smoked it. i commend you for wanting to build the slant, but it comes at a price. if you do some searching, you will find great tech threads on /6 performance mods, check out Bills turbo /6 builds. :D
 
I would say if you're worried about mileage, buy a Toyota. Slants ain't ever got great mileage. A good built and tuned 318 will beat them almost everytime. That's why you see so many people throwin slants in the ditch. If you build a slant, it ain't about goin real fast or about mileage. It's about bein different. Although there ARE some serious fast slants out there, it takes deep pockets to do it.

I am into slants because I had a dear friend Bruce (RIP) who turned me onto them. When you start learning about them and how cool they are, it's easy to get addicted.
 
Unfortunately for you USA guys, you didn't have BW diffs in your Valiants/Darts...we did....and there are heaps of ratios to pick from, from other Oz made cars with the same type diffs.
I've got a set of 4.11's from a Nissan P31 Pintara that fit straight into a 1970 Oz Valiant diff housing......yes, it's for a Slant 6......and for the 1/4 mile.
 
thanks for the help cuda! sorry if im bugging you . when u say gas milegae went down, how much? i found a rear end from an international with the 4,27s. if i were to get it would i just have to swap the differnentials and be done with it? or do i still have to get inside it and change gears out? thanks!!

I'm relying on memory from 20 years ago, so keep that in mind, but.. I think I lost 5-8 Mpg., so it was quite a bit. Do a bunch of measuring on the Scout rear before you buy it. Measure flange to flange to make sure it will work. I ran wheel adapters on mine, which were about 3/4" thick per side. The Scouts had a 5 on 5-1/2" pattern. My adapters made it a 5 on 4-1/2".

I don't remember having to move the spring perches on the axle, but measure that too. I am pretty sure I reused my driveshaft and U-joint, but you could check that first too. The Scout rear should be a Dana 44, and the tubes will be bigger than your 7.25" rear. I stretched my stock U-bolts over the 44 and made them work. Remember this was the cobbing of an 18 year old with no money. The 44 is stronger than your 7.25, but it's no wonder axle, just a cheap way of getting some low gears. If the 44 you get is serviceable, you should just have to resurrect the brakes, and make sure it is full of fresh gear oil, you shouldn't have to touch the gears. Mine was a one legger, and I eventually spun the spider gears out of it doing burnouts. If you get a Power lock one, great, if not the peg leg will be OK. You could weld the spider gears if it is a one legger, (another "cobby" low buck trick) that will get power to both tires. The 44 in my Jeep is welded.
The 4.27 geared 44 won't do a thing for mileage or driveability, I'd think about it for a while before jumping in. If you do the swap, keep your stock rear, you may hate it and want to go back.
 
:lurk:
alright my gearing is somewhere between 2.45 to a 2.73 with 7 1/4 rear end. what am i goona need to hold my own with 5.0 engines? shall i gett a whole new bigger rear end or just up the gears? thanks alot for your help guys it means alot


TO KEEP UP WITH 5.0 YOU'LL NEED A 440 AND A 8 3/4.
 
If you build a slant, it ain't about goin real fast or about mileage. It's about bein different. Although there ARE some serious fast slants out there, it takes deep pockets to do it.

I am into slants because I had a dear friend Bruce (RIP) who turned me onto them. When you start learning about them and how cool they are, it's easy to get addicted.

I wanted a slant, because I wanted a Hyper Pak. Coolest intake manifold ever!
 
alright my gearing is somewhere between 2.45 to a 2.73 with 7 1/4 rear end. what am i goona need to hold my own with 5.0 engines? shall i gett a whole new bigger rear end or just up the gears? thanks alot for your help guys it means alot

you run gears to get your engine in the right rpm build... i run 4.88's but i spin to 6 grand... your not gonna make power to 4800 unless you build it up... a 3.73 would probably be the max for you at this point... do you have anything done to your car yet?


not a mustang but it i a turbo cobalt...

[ame="http://www.youtube.com/watch?v=iouvjSfeans&feature=relmfu"]Run3.MOV - YouTube[/ame]
 
What a wise guy, Mark,,,,,,,,,It hurts but I know your right,,,,............
 
In my '75 Scamp, I went from a 7.25 with 2.76 gears to a 8.75 with 3.55's. I noticed a difference in acceleration off the line. A stock Slant 6 with 2.76's is a dog.
 
now THAT is funny , and , i hardly think so.
OK FOLKS EDUCATE ME. THIS IS MY FIRST /6 BUILD. I EXPECT IT TO DO BETTER BUT . I CAN'T SEE IT RUNNING WITH V8s that spent the same amount of money I DID ON MY 6. OR am I in for a surprise. I'm not trying to be a smart ***. I really don't know. mouse
 
if they are built up a little im think 13-11 second cars... you gonna need boost, No2, or a Very well built motor and a light car...

im just about to get into the 13's and mine a 3200 lbs car all motor, street driven... my car y no means is a benchmark but im just throwing it out there... i should have a mid 13 second setup when i get it tuned in...

to run boost or No2 you gonna need atleast forged pistons and would want K1 rods as well... thats a grand right there... the head is where your power is made... on the bottle your gonna need alot of porting and a nitrous grind...
 
-
Back
Top