I've done two Richmond 5 speed conversions.
I've put my swap on my web page. http://ourworld.compuserve.com/homep...m#Transmission
I can't vouch for the strength of the Richmond compared to the other trannys. It looked pretty good to me when I ordered it. But I don't want to come on here trying to reinforce that I made the "right" decision.
We didn't have to shorten the driveshaft of the 69 Z/28 we did. But it was close to needing it.
You do need the large shaft TH400 type yoke.
And you need a fine spline clutch disc.
The Richmond has gear ratios that are closer together than other 5 speeds like the Tremec, so you'll keep the engine in the power band better but have less top end in 5th (like over 160mph) when running a 3.08 compared to the tremec which is ovedrive in 5th.
Your driveshaft will be turning slower with the Richmond in 5th, compared to most other 5 speeds.
The 3.08 rear will have more pinion teeth engaged at any time compared to a lower gear set like 4.10. Might be less likely to break a tooth off the pinion gear.
Less wear on the diff because it's turning slower.
You might get away with keeping your low gears with a 5 speed that is overdrive, but first gear will be so low that you won't use it.
Check your rear before ordering new gears, many cars have a 3 series carrier that had a ring gear spacer plate added when lower gears were put in, and you can just remove the spacer when going to 3.08's.
Also, Richmond makes a special thin ring gear set for 3.08 ratio only, It's for use on a 4 series carrier. I've seen it, and it looks good.
I did some mods to allow the Hurst shifter to come up through the factory console.
Otherwise the stick will come up to the left and rear of the factory position.
Key to any transmission or rear end life is to allow for a good break in.
The gears (especially the ring and pinion) will make a lot of heat when breaking in and if you get on it too soon for a prolonged time, you can ruin the heat treat of the gear surfaces and soften them, shortening their life.
I've seen new rear ends get almost too hot to touch just from a half hour cruse around town.
The second half hour the temp was half what the first time was.
Check my web page for First Gen Camaro suspension info:
David's Motorsports page
First Gen Suspension Page
67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer