[skunkfunk]

The 4 speed in my '69 GTO bit the dust, which is not surprising since it was a 3.44-first-gear ST10. The existing rear end is a standard (non-posi) 12-bolt 2.73, which worked decently well with that oddball 4-speed.

I have an 8.2" 10-bolt with 3.36 posi I pulled out of a 69 firebird I wrecked (sadly, got rear ended very hard), or I could build the 12 bolt. Seems like I'd rather throw that 10-bolt in there and see how long it lives. It's rather whackadoodle, with a weird repair on the carrier - I'll try and attach a picture - but it lived just fine in that firebird, behind this same 400.

Not sure how much power I'm putting into it - this is a plain jane 400 with that stupid down-in-the-hole piston kit, #16 heads off a 68 gto I think (only lightly modified, unported. Big valve D-ports.) an ultradyne 223/231 cam if I remember from many years ago, and a performer RPM intake. Currently no headers, maybe later. Runs nice, should be good with a wide ratio transmission.

Future plans are a nice 455 with either ported 6x heads or edelbrock heads or something. Hopefully way in the future when this 400 is broken.

No plans to ever throw slicks on it or anything. It may get a few runs at test and tune just to see, but this will mostly be driven half the year daily.

I think I've settled on a TKX transmission. The 3.27 first gear and .72 overdrive sound nice, but the close ratio should also work well enough with 3.36 gears. So, my questions are, is this a good plan, or would you guys like to talk me out of anything here? 3.36 8.2" 10-bolt from the firebird into the rear (yeah, some modifications needed) and see how long it lives, and the wide ratio TKX. Is that first gear gonna be a granny gear with a 3.36 and stock-ish tires? I run 255/60r15 currently.

If that's a bad plan, plan B is to build that 12 bolt with 3.73 posi and get the close ratio TKX (2.87 first and .68 overdrive), but it'd sure be a lot cooler and cheaper to use up that old rearend and just keep the 12 bolt to build if I ever break it.