70 pulleys

[Dennis D.]

Having trouble zero-ing in on the correct part #s for the crank and WP pulleys for a L-46, non A/C, PS. Also fan blade, clutch numbers. Found I have all 71 stuff up front. Been there since 73 when I bought it.

I know,not broke,don't fix it. Lousy weather in the NE, nothing better to do.

[Joe L.]

Re: 70 pulleys

Dennis-----

It's not too complicated. The ORIGINAL crank pulley for your application was GM #3858533. It's still available from GM to this very day. The waterpump pulley was GM #3848904. That pulley was discontinued 30 years ago and replaced by GM #3995641 which remains available to this day.

Fan blade was GM #3888366, a 5 blade unit of 17-1/2" OD. However, I've heard of cases of 1970 with L-46 and without C-60 using the C-60 fan blade. This was GM #3955182 and was a 17-1/2", 7 blade fan. Both fans are GM-discontinued.

Fan clutch used originally was VERY likely GM #3937771, a Sweitzer-manufactured unit with "bi-metallic plate" style thermostat. GM #3916139, a virtually identical appearing unit, may also have been used. These numbers will not appear anywhere on the fan clutch and both of these have been discontinued for years.

[Dennis D.]

thanks joe *NM*

[Chuck S.]

Re: 70 pulleys

Dennis, any chance your car is a very late 70? Does the engine appear to be original to the car, and what is the engine build date? Maybe it ain't "broke" at all...two years is pretty short time to get all the pulleys "Bubberized" on an almost new Corvette.

[Dennis D.]

Re: 70 pulleys

chuck

Original engine. June 16 build date. "bubberized", I suspect.

BTW, the drivetrain was "71 vintage", as well.(driveshaft, yoke,trans.) Corrected all those issuses. Thanks

[Joe L.]

Re: 70 pulleys

Chuck and Dennis-----

I agree. I don't see how the pullies could have gotten changed if the history of the car is positively known back to 1973, or so. On the other hand, it would really surprise me if any 1970s were built with the 1971 pulley system configuration. I would much more expect that some early 1971s were built with the 1970 pulley system.

Is it known if the car still has its original water pump? If so, what is the casting number?

[Chuck S.]

Re: 70 pulleys

So the trans definitely had a 71 VIN derivative?

Hmmmm...Relatively new car with 71 MY components: it's almost like it was a dealer-inspired swap from a 71 donor car to get spare parts quickly. That practice would seem inconceivable, but I have seen it happen on a more common car...probably illegal as heck to swap VIN numbered components too.

Ever look to see if the tank sheet is there?

BTW, June 16 would not be a VERY late 70 engine build. That would be about six weeks before the end of production. I was thinking that they may have run short of L46s and moved engines produced for 71 MY into very late 70, but I doubt they would have missed their target by six weeks of production. With other driveline components changed, funny business has definitely transpired.

[Dennis D.]

Re: 70 pulleys

Have the tank sheet. (replaced the tank though). Water pump was a 71 also. (have replacement piece). All dated engine pieces are 70.(heads, block,etc).

Don't see any damage, but I guess there could have been, and parts were replaced at the time from a 71 .