This is the VERY hard to find sealer that GM used "back in the day." I am told there was a Service Bulletin that addressed complaints about rough idle on the tripower cars. The bulletin described how to apply the sealer and directed the mechanic to the parts counter for a small vile of sealer, a small paint brush, and directions. DAG213 does an excellent job,. but will not help badly pitted throttleblades, or badly pitted bores. I use this product on all the end carb throttlebodies I restore. I have seen some criticize this product. Hmmm. Can't understand that. You want a good idle, you need to have the end carb throttleblades sealed the best you can. I still find it on some of the end carbs I restore. I have heard some criticize this product, saying that comes off with carb cleaner. Might be so. But, why would you spray carb cleaner down an end carb, anyway? So, if you use the sealer, don't use carb cleaner. It is hard to find for several reasons...1) Suppiers sell it in large quantities..like a gallon for over 500. 2) It has a 24 month shelf life from time of manufacture. Here is the deal...if you buy the DVD I sell on the page..it includes instructions for application. Shows a video of me, applying the sealer, in fact. AND if you buy a set of rebuild kits....I will give you the DAG 213 sealer. But, you will need to remind me of this... there is a place for notes to me when you are checking out. If you miss this...send me a short e-mail. Again, to be clear, buy the DVD and the carbs kits and the DAG213 is included at no charge. Otherwise, it is 15.00. There will be enough to seal several sets of throttleblades. Know, though, that the sealer will not last long in the small tube I send you. So, I suggest using it within 30 days. I would recommend keeping it in the refrigerator for a longer life.