Buzzed the car around for a little but last night for the first time after the tune, was was able to get into it finally. It kept wanting to throw the belt at higher RPMs. Been reading on tensioners and other causes, I don't see any pully alignment issues, and I'm pretty confident the tensioner is just weak. Upon searching, I couldn't find reasons on why one was better than another, and just looking for a little more info on whether to buy a solid tensioner, or a stock replacement with the higher ribbed 3800supercharged pully......I've read good and bad about both.

 

Do not know about solid tensioners on these cars, but lived with a solid chain tensioner on my race car's motor (see avatar). On my Suzuki 1000 it was the only way to go in that situation, but you were always worrying about getting it right. Always.
Have not heard the topic brought up here, so maybe you just need a new stock one with proper spring tension.
Good luck.

 

Serp belts are not meant to have static tension across them regardless of how many people use them and how many miles they have on them. They're simply not designed for that type of use

A good working tensioner and pulley are what you need

 

Is there a deeper rib pully that would help out along with a new tensioner?

 

I got a Gates #38009, but never used it. Got the number (some time ago) off the Corvette Forum. It is bigger. $10- shipped, if you want it. However, you may need a longer belt. Also, it could move the belt to where there are clearance problems. Guys who put the number forward swore by it. Me.... I don't think it's necessary. Like Pocket says, a new tensioner should work just fine.
LMK if you want it, or pic.

 

I'll order a new tensioner, and if I still jar issues I'll keep you in mind.

 

After replacing with stock replacement tensioner, I have had zero issues. The spring tension and pully seemed fine, it was the actual pivot point of the tensioner that was worn, allowing the spring loaded arm to moved from the front of the car, towards the rear of the car about 1/4 inch.

 

That is the most common tensioner failure. The pulley bearings also fail allowing a wobble

Symptoms are a frayed edge on the belt onset moving to tossing (and eating) the belt

 

Not sure why a manual belt tensioner is a bad idea, I know a lot of Imports and chryslers used them (atleast in the 90s) without issue. I like the automatic tensioner better though, no worries about adjustments, and saved 60 bucks. Still carrying a spare with me just incase. Maybe somebody will find this in the future and look for the arm having slack and jus just spring tension and the pully, I know I didn't initially think about it.

 

My car threw belts all the time even with the deep groove pulley and new tensioner on it. Solid tensioner is on all the fast cars that rev quickly and tensioner won't keep up with big stalls.