Is Slick 50 any good?

I bought a bottle of Slick 50 for my 85 Cap Classic...the engine is starting to knock and I cannot afford to fix/replace it at this time. I was thinking this stuff might bide me through until I can afford to do something with the engine. But is it any good, or just a load of hooey?

How many miles are on the engine? Can you pinpoint the source of the knock at all (or a general area of the engine). Did it start to knock before or after the adding of the slick 50? I've never used it before, so I'm not sure about its being good or bad. I do know that Lucas oil does wonders for engines and trannys. I definately noticed a difference in my car. Try changing the oil, and use 4 quarts of 10w30, and 1 quart of Lucas engine oil. Keep us posted on what happens.

I haven't added the Slick 50 just yet, took the car in and got oil changed at which time they also did a flush and Wynn Oil Treatment. It seems to run a little quieter now but can still hear the knocking slightly (more of course when you accelerate). I got stuck outside of town last year when the engine suddenly overheated. In order to get to a place where could put any water in it, I let it cool down and then made a run for it...by time got home temp guage was pinned and she was huffing.

Turns out must have a pin leak in head gasket since there is no sign of coolant loss anywhere but the coolant was gone. I put some stop leak stuff into her and that seemed to stop the coolant loss, but damage was already done to the engine. Been knocking since.
The engine has 150,000 kms on it. Wish nice if I had a garage or something cuz I'd like to be able to pull the engine and rebuild it. Like the car (wife don't) but can't afford much hence the Slick 50.