70 454 engine belts quandry

[Chris H.]

Does anyone know if 70 engine belts had both “cut” construction and “cloth wrapped” construction? The water pump belt from Quanta is the cut style, but the alternator (non-power steering) is cloth wrapped.

I’m having a heck of a time getting an alternator belt that is the correct size (length / width / thickness) for my 454. Repro catalogs say the alternator belt length is 53 inches, but I know that the belt has to be at least 55 inches.

Any assistance appreciated. Thanks, Chris

[Joe L.]

Re: 70 454 engine belts quandry

Chris----

The original alternator belt for the 1970 LS-5 non p/s application was GM #3940991. This belt was 15/32" wide and 53-1/2" long. As far as I know, it was of "wrapped" construction as very few belts prior to 1973 were "cut". However, due to its "oddball" width, it's POSSIBLE that it was of "cut" construction. I can't confirm it one way or the other. This belt was used in PRODUCTION and also available in SERVICE until April, 1973 when it was replaced for SERVICE by GM #3845654. The latter belt is 3/8" wide and 53-1/2" long and is of "wrapped" construction. I think that it's even POSSIBLE that the GM #3845654 belt was actually used in PRODUCTION for the 1970 Corvette LS-5 application. Due to its narrower width, it would be, effectively, "longer" as far as installation goes.

The original water pump belt for 1970 LS-5 applications was GM #3952336. This belt was 15/32" wide and 31-7/8" long. As far as I know, this belt was also of "wrapped" construction. However, once again, due to its "oddball" width", it's POSSIBLE that it was of the "cut" type. It was available in SERVICE from GM for many years, but was discontinued without supercession several years ago.