Dumb intake manifold idea and axle question

Hey everyone. Today I propose yet another dumb idea that won't work. But it's worth a shot. I was thinking about the intake manifold and how bad it is when I thought what if I cut off that old log manifold and weld on my own intake with equal length runners and smooth walls. Is that somewhat of a good idea or completely insane. And my axle question is according to the falcon handbook I have a 3.10 to 1 but the shop manual says 3.89 to 1. If I really have a 3.89 to 1 just to go 65 is 3,400 rpm. So I would need an axle swap. Would a 8" out of a 63 Fairlane like this work. Thanks everyone

https://www.ebay.com/p/1963-Fairlane-9- ... 2205261550

that may B an 8 inch? as written lower in the add. Looks to have big bearing ends for larger wheel bearings, may B too long (Fairlane) for the falcon (needs cutting dwn). So no on 3 counts? That's my uninformed quick guess anyway.

I thought U decided U did not need the "hulkin 9 inch" in ur lill car?

falcon_master":1hhw1tz0 said:

Hey everyone. Today I propose yet another dumb idea that won't work. But it's worth a shot. I was thinking about the intake manifold and how bad it is when I thought what if I cut off that old log manifold and weld on my own intake with equal length runners and smooth walls. Is that somewhat of a good idea or completely insane. And my axle question is according to the falcon handbook I have a 3.10 to 1 but the shop manual says 3.89 to 1. If I really have a 3.89 to 1 just to go 65 is 3,400 rpm. So I would need an axle swap. Would a 8" out of a 63 Fairlane like this work. Thanks everyone

https://www.ebay.com/p/1963-Fairlane-9- ... 2205261550

Click to expand...

if you decide to cut off the log, make the intake removeable instead of welding on a new one, it makes it easier to port the heads, and do whatever maintenance might be necessary.

as for the rear end, that is an 8" rear end not a 9". you will probably have to narrow it a couple of inches to fit your falcon. not a problem though, just make it the same width as your falcon rear end, and then order axles the same length as the falcons axles are now. that gives you the option of keeping the four lug wheel pattern, changing it to fit something like the fox body wheels, or upgrading to five lug wheels.

I originally didn't care because I wasn't going to be putting alot of power through but of the shop manual is correct then the 3.89 final drive ratio is just to low for me. Just to go on the freeway I'll be turning 3,400-3,500. That's just too much for me to be comfortable with. And if I compensate with tires I'll need massive tores to make up for the ratio and that'll destroy what little acceleration I have. So it seems better to me to get a rear end that has many ratios available and stick like a 3.10 or 3.20 in it and use 24" tires.

On this subject I just found another donor. A 9" from a 70 or 71 351 ranchero. With posi traction.

"That's just too much for me to be comfortable with"
don't know what U have now but U could just change the ring'n pinion w/o all the weight'n futzin w/the wrong housing length, etc.

https://www.summitracing.com/search/par ... nion-gears

the set up is difficult as U hafta mesh the gears properly (have another do it?) but even this could B cheeper in the long run. Just depends on what;s around U...

If he has the 7.5 inch rear end,ring and pinion gears are like UNICORNS.Lotsa luck finding some.
Good luck.Have fun.Be safe.
Leo

Your car stock should have a 3.5 ratio 7.25 rear. Thats what someone swapped into my car. Also, that same year they had V8s in your same car so that means they have 8"s that will fit. Look for an early 8" for a easy swap, no mods except for the new v8 yoke and possibly the brakes but all simple bolt on stuff.

Your car with an auto came likely with a 3.1, with a manual it should be a 3.5. Which means you're turning about 3k rpm With 25" tires. Slightly higher like maybe 50-100 more with 24".

The prob with a 9" is that they're very heavy and overkill for a l6, especially for a 144 or 170. If you plan to put a spooky hopped up 302 or something then the 9" is the way to go but the price will be a lot of work to shorten and crap.

Your car came with either a 7.25, a 7.5 (For the Rancheros and maybe wagons, not sure), or the 8". Stick with something that was made for the car and it will make the process much smoother, cheaper, and easier.

Also, to check if its a 8" or the 7.25, check the rear of the diff. If you have bolts on the back and can take a plate off to access the guts, then its the 7.25 or 7.5, if not and the access is from the front and the hole carrier has to be pulled, then thats the 8".

I did this swap from a 7.25 to an 8" and it wasnt hard but it wasnt great. It was $140 to cut the driveshaft, weld the new yoke on, and balance it, thsts cheap. Plus i paid $250 for the rear. It came with new 10" brakes on it but the wheel cylinders were dried up and nasty and it needed new auto adjust linkage, so about $40 for the new cylinders and $20 for the new auto adjust stuff. Then about $120 for ebrake stuff since it didnt have it and the original stuff wont work with it.

Good luck man,
Ryan