I have an A and an F (stock) mainshaft, which should I use for my V8 conversion? I think I know the answer, but I thought I'd get some confirmation. These are both ratios that would be in the second gear position, and not subject to the "cantilevered first gear" weakness. F is the stock second gear ratio, and is what most V8 conversions use. My gut feeling is that the A ratio (same as the stock 914 first gear) is way too low for a V8, but F seems a bit high (stock 914 second gear ratio)

I will be using an H flipped as "4th" gear (in place of 5th), and will be spacing out "2nd" and "3rd" based on the "1st" gear choice, using what gears I have.

First gear in a 914 with a v8 is really low. Never used it never had a desire to. Not to mention you shouldn't use it. I think that the stock 2nd gear is a tad high but very usable. If your choices are to use a "1st" gear ratio vs "2nd" gear ratio i would go with the 2nd gear ratio. My engine has about 280 hp and 330 ft/lbs tq. I'm running a stock tranny . Use the second gear ratio.

or you could find an 'E' 2nd gear mainshaft ...

Charlie Davis' website shows the transmission type numbers that used the 'E' 2nd. cross-referencing those back to ccar models is left as an exercise to the student, but the information should be in Anderson, Barth's 'The Porsche Book' and 'Excellence was expected' ...

1st is MUCH too low and will cause breakage.
Use 2nd ... MUCH smoother yet still allows burnouts, not that you would EVER do that !!!
H conversion is also a GOOD idea.
Good luck ...

Currently, I broke my throttle cable... Sooooooo Im using a 2k idle, and first and second to get around the block.. Then just coast around at 15...

ahh the joys!!!

Cool, thanks. That's pretty much what I thought, just wanted to hear it from others

That makes these my chosen ratios:

"1st" F 18:34
"2nd" V flipped 25:27
"3rd" ZD 31:22
"4th" H flipped 32:19

Which, if I'm not mistaken is what they say to do anyways, which means all my math effort was a waste of time Looks like all I can use from the 912 4 speed is the H gear (and the nifty magnetic drain plug) Does anyone know if the intermediate plate or differential cover are interchangable? They are both aluminum and should be stronger.