Not sure about your calculations. When I plugged the info into the site, I got this:

1945 rpm, 3.50 gear ratio, 1:1 final drive, 26" tire, 43 mph.

Considering your sped limit, I would have no problem with 3.5 or 3.70 with your engine/trans combo

 

Your calculations are close to mine with the difference of 10 rpm lower on my calculaton:-
My calcs:- 3.50 gear ratio, 1935 rpm, 1:1 final drive, 26" tyre, 43mph
Your calcs:- 3.50 gear ratio, 1945 rpm, 1:1 final drive, 26" tire, 43 mph


The difference between the 3.5 and the 3.25 is:-
3.25 gear ratio, 1797 rpm, 1.1 final drive on a 26" tyre at 43 mph.
3.50 gear ratio, 1935 rpm, 1.1 final drive on a 26" tyre at 43 mph.


The difference will be 100 rpm lower on the 3.25 gears than the 3.50 gears. I do not really know if anyone can notice the difference between the two in real life??? Isn't it.......

 

When comparing my friends pre 3.9 gear ratio with post 3.23 gear ratio it comes the below:-

3.23 gear ratio, 43 mph, 1725 rpm, 27" tyre (my friend post gear swap)
3.90 gear ratio, 43 mph, 2083 rpm, 27" tyre (my friend pre gear swap)

The 3.23 gear makes 300 rpm less at 43 mph than the 3.90 gear and considering that my friend is more happy in real life with the 3.23 gear set. (300 less rpm)


The below are the gears for better comparison.
3.23 ratio, 1725 rpm, 1.1 final drive, 27" tyre at 43 mph (my friend post gear swap)
3.90 ratio, 2083 rpm, 1.1 final drive, 27" tyre at 43 mph (my friend pre gear swap)
3.25 ratio, 1797 rpm, 1.1 final drive on a 26" tyre at 43 mph (my option 1)
3.50 ratio, 1935 rpm, 1.1 final drive on a 26" tyre at 43 mph (my option 2)

 

I still wouldn't have any concerns with going fairly low at your speed limit. My big concern would be going too high a ratio, and loading up the engine when the trans is in 3rd gear 1:1 ratio. If you go with 3.20 or even 3.50, you might find the engine doesn't like cruising around under 2,000 rpm, and have to shift down to 2nd to get the engine to run cleaner. I'd rather run 3.73 or 3.90, and be able to use top gear.
I run into this problem with my 464 BBC when cruising around our city streets at the posted 35 mph speed. 4th gear in my 4 speed tends to let the engine load up, and it surges. I have to run 3rd gear, which is a bit lower and cleans it up, but higher rpm than I like. If I had a shorter tire, or more rear gear, I could cruise and not load up the engine.
Think about what speed your engine will spend most of it's time at, and gear the axle for that speed, and just over 2,000 rpm. Your engine will appreciate it. Also call your engine builder, and ask him what rpm he thinks the engine will run best for a constant cruise rpm.

 

Hi, Thanks for the reply. As soon as I have feedback from the engine builder, will let you know the answer.

 

Back to the garage.... Spent 2 days cleaning my garage and sorting all the parts. Was like a mess with parts and cartoon boxes piling up.






It is very nice to work in a clean environment and fresh air now that the temperature starts to rise... 17 degrees C

 

Today I am mating the front frame back to the car. New bushings for the frame.


I am finding a problem to align the front frame to the body. There is a lot of movement fore and aft and sideways. Any tips please how to align the centre of the front frame with the centre line of the car?


There is a 3/4" whole in the bottom of the cross member, is this located in the center? Can I use it as my centreline of the front frame?


Any help is appreciated.

 

Really kinda late now. But you should have taken measurements prior to disassembly, and written them down for later reassembly. Now you'll need to assemble it loosely, and measure wheelbase length and compare to factory specs. Then cross measure from a corner point at the opposite rear, to front on both sides, and square it up. Still you'll most likely have to loosen and make final adjustments once the front fenders go on, as it might need some adjustment for panel gaps. There are alignment holes that will get you close, but you'll need a "story pole" to get it perfect. These are usually just made up from a long piece of stiff tubing that you can clamp a pointer on each end to match a specific place on each corner. Then corner to corner comparisons to determine how much needs to be moved to align it perfectly.
I recommend you get the book on restoring Camaros, for some help in numerous areas you'll face.
Trans Am & Firebird Restoration: 1970-1/2 to 1981 by Melvin Benzaquen | 9781613251720 | Paperback | Barnes & Noble

You'll have an added issue with the new 4 link you've chosen, as it wont be set in place like the stock leaf spring setup. So your measurements will have to be to mounting holes at the rear for now, and then the new 4 link can be set to determined places at the front later. You'll be making lots of measurements on the same things over and over! Then readjusting as needed the further along you get!

 

The front subframe mounts have alignment holes. Get 2 dowels the diameter of the holes and slide them through the mounts and up into the holes in the body. When the dowels on both sides are straight up and down (front to back, side to side), you should be pretty close. Then you can do your cross measurements from there to fine tune the fit, if necessary.

 

Hi, thanks for your feedback. I have been searching and reading of how to do it. From the videos looks easy but when you actually doing it, it is more difficult.


I took the measurements of the front frame alone (A, B, C, D, E, F, G) as per the Under Body Section 3 Fig 3-1 and all the measurements are found to be within 1/8" of the manual.


There is only one particular measurement from the centre of the 5/8" master gage hole adjacent to the no. 1 body mount to the centre of the no. 2 body mount location on the same side of the frame which measurement did not conform with the manual.


The manual says to be 32 7/8" centre to centre while I measured 29 9/16" centre to centre. This is on both sides. Could not be that the frame is bent. because all the dimensions are correct. Has any one encountered this problem before or has the correct dimension?


Or maybe I am doing something wrong?