As it sits, car is this:

69 Cuda. 3500 lbs with driver.

418 stroker

3:91 727 w/ Tight 10" TA converter.

M/T drag radials 275/50/15.

Stock suspension.

Best time so far is 11.26 @ 119. 7.15 1/8 1.54 60ft.

Pretty sure that was leaving a lot on the table due to little tuning. That said, I bought a Dana a few months ago and we are yet to install it. It has a 4:10 in it, so I'm going from a 3:91 to a 4:10. The car has no cage, so we were hoping for street-able mid to high 11s when we built the stroker, and were surprised by the monster it turned out to be. We would like to run as close to 11.50-11.60 as well can to stay out of trouble. A 3.54 would make it even more street friendly and tame the launch just a bit. The only problem could be the 727. It is basically a stock rebuild with a shift kit. A 3.54 would put more stress on the trans, especially with that kind of HP and TQ. Car sees mostly street duty and the track 5 times max per year. Would a 3.54 be smart move to tame it a bit, or would we be asking for trouble?...

We are novices at low 11/high 10 sec cars, so all constructive input is welcome.

Thanks

How is the drop in gear ratio going to hurt the 727?

I have read, and been told that going to higher (more street friendly) gear, creates more stress in the trans and rear end. So, I'm asking how much stress difference we are talking 4:10 vs 3:54?

You should be fine. The 727 is a strong trans. I built the 727 on my boys 400 Dart and I used all stock Mopar clutches and seals. Since I worked 25 years for Dodge dealers I had a few laying around. That trans has been in the car since 1997 as it was behind the 383 first for about 6 years and the rest of the time behind the 400 which gets raced a few times a year and has run 11.40's with 3.91's. That trans fluid still looks nice and red (changed it about 2 years ago) and the trans has never had any problem. He has not driven it alot the last year so thats why I did not change the fluid last year. But it has been trouble free for 15 years and the one in my 63 has stock Mopar clutches also and it has been in the car since 2006 with zero trouble. I think you will be fine. Ron

I would run it with the 4.10. If it is too fast, short-shift it or pull some timing out. Or go to a vacuum-secondary carb on it and put a stiff spring in the secondaries.

i don't think you have enough tire to hurt anything except the engine when they break loose. back in the day we ran a 68 dart 440 and hemi 14-32 tire and didn't matter what gear, 4.10 to 5.38 pretty much ran same thing, just made converter work more, stock trans with vb. 1978 we ran 10.30 with hemi and 10.80 with 440. one trans. 6 years. 3.54 will give better cruise rpm.