I have TKO 600's in both my cars and was surprised how much more of a PIA it was to fit the Camaro. The vette tranny went right in with no driveline issues but the Camaro didnt wanna play nice. I ended up 4 degrees down using the stock engine and tranny mounts which was out of parameters and was causing a vibration in 5th gear above 2500rpm. Tranny had to be shimmed up at the x-member which caused interference issues with the tunnel. Like someone said above, the issue for me was with the flat square top on the TKO. The square transmission top was contacting the tunnel on the passenger side in the front corner which resulted in having to make a small clearance cut to give it some wiggle room. Once done, all vibration and clearance issues solved and I'm very happy with its performance. As mentioned above, critical aspects of transmission and rear gear selection are induction type (carb or EFI) rear tire height, and cam profile. Often I see people making recommendations on rear gear and transmission overdrive ratios without these important factors being mentioned or considered. A mild cam with EFI will be much more tolerant running at 1800-2000rpm vs a moderate cam with a big Holley carb. I went with the .64 OD TKO for the Camaro and while building up the rear end switched from a 3:73 posi to a 4.10 trutrac. Rest of the equation is a 27 inch rear tire (255/60x15) 224/230 hydraulic roller cam and 650 DP Holley. The old 3:73 rear axle had me running 80+mph to be in the sweet spot cruising at 2500rpm, the 4.10 rear now puts that same 2500rpm at a very freeway friendly 74mph. I've seen some concern for 1st being too short with 4.10 but I don't see it as my normal everyday 1-2nd shift is around 3500rpm which is 25mph. To take advantage of the extra rear gear in 1st I replaced the heavy 36 lb Centerforce flywheel I was running along with their equally heavy Dual friction clutch and swapped in a Hays 25 lb flywheel and street strip clutch. Dropping 11 lbs on the flywheel and 5 lbs on the clutch made a huge difference, the motor spools up much nicer now and the increase in engine braking makes for a very fun driving experience. When I set up my 69 vette I went with the .82 OD TKO as it was going into a sub 3000lb car with 3:73 out back and a 440hp sbc with a light flywheel and clutch. I had some folks tell me not to run the 15 lb GM flywheel in a 100% street car but I did it anyway and its absolutely phenomenal to drive. It has a 224/230 hyd roller as well with a Chuck Nuytten built 750 HP with a 27 inch tire (255/50x17) and the car runs 2800 rpm at 75mph. With the purpose built carb it actually surprised me how clean it runs down low in top gear. I don't make a habit of it but it will run 2000 rpm in 5th just as clean as can be with no driveline lash as you might expect from the light clutch/flywheel setup. Paid thru the nose for it but its the best carb I've ever run. As far as the TKO shift issues I have read about at higher rpm, I have not had any issues as both my cars are hyd roller and are setup to be done by 6000 rpm.