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**71CHEVYSHORTBED402** · 03-12-2024, 12:12 AM

I wanted to see the performance specs. for 1969 through 1974 Trans AMs. Then thought to compare that to Z28s. Made a small project of it, please let me know if you see an error, I'll straighten it up. Unfortunately an image is too small to read, sorry

I'll paste the data here....

Car - Engines Available - Compression - Torque @ RPM - HP - 0-60 Time - Quarter Mile - Comments

1969 Trans Am Ram Air III and IV, 400, 4 bolt main - 10.5:1, and 10.75:1 - 430 @ 3400, and 430 @ 3700 - 330-345 - 5.4-6.5 - 13.7-14.2

1969 Z28 302, 4 bolt main - 11.0:1 - 290 @ 4200 - 290 - 7.4 - 14.8

1969 Camaro 427 - Yenko Camaro 427 - 4 bolt main - 11.0:1 - 460 @ 4000 - 430-450 - 5.4 -12.59 -"For comparison. 427s were options in Camaros, but not Z28s. 427 data is limited to the 1969 year, for this writing.

1970 Trans Am Ram Air III & IV 400, 4 bolt main - 10.5:1, and 10.75:1 - 430 @ 3400, and 430 @ 3700 - 335-345 - 5.4-5.6 - 13.9-14.9

1970 Z28 350 LT1, 4 bolt main - 11.0:1 - 370 @ 4000 - 360 - 5.3-5.8 - 13.9-14.2

1971 Trans Am 455 High Output, 4 bolt main - 8.4:1 - 480 @ 3600 -340-345 - 5.4-5.9 - 14.3

1971 Z28 350 LT1, 4 bolt main -9.0.1 - 360 @ 4000 - 330 - 6.6 -14.5

1972 Trans Am 455 High Output, 4 bolt main - 8.4:1 - 415 @ 3600 - 345 - 5.4-5.8 - 14.3

1972 Z28 350 LT1, 4 bolt main -9.0.1 - 280 @ 4000 -10 less HP than the 1971 Z28 - 6.5 - 15

1973 Trans Am 455, and 455 Super Duty (SD) 4 bolt main - 8.0:1 - 370 @ 3400, and 390 @ 3400 - 250, and 290-310 - 5.6 - 13.75-14.3 - 0-60, and Quarter Mile times are for the 455 SD.

1973 Z28 350 L82, 4 bolt main - 9.0:1 - 280 @ 4000 - 10 less HP than the 1972 Z28 - 6.7 - 15.2

1974 Trans Am 400, 455, and 455 Super Duty (SD) 4 bolt main - 8:0:1, and 8.4:1 - 330 @ 2800, 355 @ 2800, and 395 @ 3200 - 240, 250, and 290 - 7.5, and 5.8 - 15.8, and 13.75-14.3 0-60, and - Quarter Mile times are for the 400, and the 455 SD.

1974 Z28 350 L82, 4 bolt main - 9.0:1 - 280 @ 4000 - See 1973 Z28 - 7-7.8 - 15.5

The performance measures are per research, though may not reflect official specifications. Ranges are provided where source data is found conflicting.

Some Sources:
https://www.nastyz28.com/camaro/z28lt1.html
https://www.thepontiactransampage.com/engspec.html
https://www.pontiactransamforum.com/...d-trans-am.14/
https://www.nastyz28.com/camaro/camaro73.html#73-z28
https://www.chevyhardcore.com/featur...nd-generation/

03-12-2024, 12:12 AM	#28
71CHEVYSHORTBED402 Senior Member Join Date: Feb 2009 Location: Northern Nevada Posts: 7,129	Re: Trans Ams I wanted to see the performance specs. for 1969 through 1974 Trans AMs. Then thought to compare that to Z28s. Made a small project of it, please let me know if you see an error, I'll straighten it up. Unfortunately an image is too small to read, sorry I'll paste the data here.... Car - Engines Available - Compression - Torque @ RPM - HP - 0-60 Time - Quarter Mile - Comments 1969 Trans Am Ram Air III and IV, 400, 4 bolt main - 10.5:1, and 10.75:1 - 430 @ 3400, and 430 @ 3700 - 330-345 - 5.4-6.5 - 13.7-14.2 1969 Z28 302, 4 bolt main - 11.0:1 - 290 @ 4200 - 290 - 7.4 - 14.8 1969 Camaro 427 - Yenko Camaro 427 - 4 bolt main - 11.0:1 - 460 @ 4000 - 430-450 - 5.4 -12.59 -"For comparison. 427s were options in Camaros, but not Z28s. 427 data is limited to the 1969 year, for this writing. 1970 Trans Am Ram Air III & IV 400, 4 bolt main - 10.5:1, and 10.75:1 - 430 @ 3400, and 430 @ 3700 - 335-345 - 5.4-5.6 - 13.9-14.9 1970 Z28 350 LT1, 4 bolt main - 11.0:1 - 370 @ 4000 - 360 - 5.3-5.8 - 13.9-14.2 1971 Trans Am 455 High Output, 4 bolt main - 8.4:1 - 480 @ 3600 -340-345 - 5.4-5.9 - 14.3 1971 Z28 350 LT1, 4 bolt main -9.0.1 - 360 @ 4000 - 330 - 6.6 -14.5 1972 Trans Am 455 High Output, 4 bolt main - 8.4:1 - 415 @ 3600 - 345 - 5.4-5.8 - 14.3 1972 Z28 350 LT1, 4 bolt main -9.0.1 - 280 @ 4000 -10 less HP than the 1971 Z28 - 6.5 - 15 1973 Trans Am 455, and 455 Super Duty (SD) 4 bolt main - 8.0:1 - 370 @ 3400, and 390 @ 3400 - 250, and 290-310 - 5.6 - 13.75-14.3 - 0-60, and Quarter Mile times are for the 455 SD. 1973 Z28 350 L82, 4 bolt main - 9.0:1 - 280 @ 4000 - 10 less HP than the 1972 Z28 - 6.7 - 15.2 1974 Trans Am 400, 455, and 455 Super Duty (SD) 4 bolt main - 8:0:1, and 8.4:1 - 330 @ 2800, 355 @ 2800, and 395 @ 3200 - 240, 250, and 290 - 7.5, and 5.8 - 15.8, and 13.75-14.3 0-60, and - Quarter Mile times are for the 400, and the 455 SD. 1974 Z28 350 L82, 4 bolt main - 9.0:1 - 280 @ 4000 - See 1973 Z28 - 7-7.8 - 15.5 The performance measures are per research, though may not reflect official specifications. Ranges are provided where source data is found conflicting. Some Sources: https://www.nastyz28.com/camaro/z28lt1.html https://www.thepontiactransampage.com/engspec.html https://www.pontiactransamforum.com/...d-trans-am.14/ https://www.nastyz28.com/camaro/camaro73.html#73-z28 https://www.chevyhardcore.com/featur...nd-generation/ Attached Images __________________ Tony 71 Custom Deluxe, SWB, 2WD, 402, A/C. I developed an assm. guide "kit" for restoring it from ground up. With assys, the guide accts for 1000s details such as OEM identifications& part numbers, written in short order. 700+ images include assm, illust., charts, and points of interest. Much of the info. applies to all 67-72 GM trucks, and to a lessor degree all 67-72 GM vehicles. My build thread, and more on the guide https://67-72chevytrucks.com/vboard/...d.php?t=730025 Last edited by 71CHEVYSHORTBED402; 03-12-2024 at 12:34 AM.