I was playing around with a governor recalibration kit today for a 70 chevelle with a 454 and TH400. Car used to shift at 5250 RPM which was too soon. I now have it shifting at 5500 in drive and it will governor shift if locked in first at 6000 RPM. I don't think this is too much to ask of it, however I ran in to some issues because of it. First time out I overreved the engine twice to 6500 RPM, It popped a few times but that is all. I drove it home, Changed wieghts and springs again then went to leave the garage and it made some banging noises and threw the alternator belt. We got a new one. Now it holds on at 5500 rpm, but if I lock it in 1st gear the belt flips inside out on the pulley at 6000 RPM. Anybody know of a good fix? Also now the car is making a strange whistle sound at idle, about 1500-2000 rpm, and when decelerating. Any clues as to what happened and how to fix? I have not been able to locate the source of the noise at all. Thanks in advance.

Once you throw a belt or turn it over it is junk.You will have nothing but the same problems with it.Get a new one.

The only belt I have never had a problem with is the Dayco Top Cog.I little more expensive but worth it.

Another belt that has a good reputation is the Goodyear Gatorback.I have never used them so I can't say much about them.

Both belts are used by NASCAR.

sounds like a vacuum cap flew of when the motor popped had that happen a few times on the vacuum tree......whistle when you let out of it because the engine has high vacuum and it will do that ......so look for vacuum leak......as far as the belt throwing thing is this the first time for going this high in the rpm range?...........i ran for yours below 5500 rpms with out throwing belts but as soon as i went higher oppps it was showing up......belts dont stay on my after they are thrown ive ran belts that have been twisted up and messed up and they would stay on for normal driving but the will continue to throw...........one thing that might help if all your pulleys are fine be sure to break in the belt....before you get on it........i had a trunk full of belts before i decided to read the instuctions on them.....the cogged back belts did seem to work better then the cheapy 2 or 3 dollar ones and put it on put some miles on the belt like 25 or so then retighten agin to i think 1/2" play in the widest spread........before you get on it again give the belt every chance to stretch during break in......hope this helps.....

i just changed the rear throttle blade adjustment on my 750 carb. opened it just a tad more. now i notice the whistle inside the carb just off idle. could the backfire caused the blades to not return to there original position? just and idea. Dave

Well I figured it out. The alternator bearings didn't like being revved to 6700 and went the roasty toasty route. They would literally whistle and 2000 rpm. Replaced with a reman unit with a new machined pulley to replaced the warped stamped steel one. Noise gone.

I use to have that problem also. I installed a deep groove pulley on the altenator and a Gates belt from NAPA. Problem solved.

i flipped my alternator upside down and mounted it low on the passenger side. the shorter the belt the less likely it is to toss 'em. i had stock pulleys and cheapo belts and never threw one after i did that and i hit 7000+ accidently on a few occasions and shifted regularly at 6200-6500rpms. a buddy did the same on his 427 and it saw regular 7200rpm shifts without a problem.

My son is having the same problem (throwing belts) where can I get a deeper alternator pulley?

I've tossed Top Cogs and Gator Backs. My alternator was a little out of alignment. I added washers behind brackets until I got it just right. No more tossed belts. But the damage was done to the alternator. I cooked my 140 amp PowerMaster a few months later. :mad:

Now I check all of my belt driven units for alignment and futz with them till they're as perfect as I can get. No more tossing.

Yup,true story.

The most important thing is to make sure your pulleys are in alignment.

If your pulleys are slightly out of alignment, no belt in the world is going to help you.

It is the first thing you should do to keep your belts in check.