1970 Corvette LT1/ZR1 Radiator hoses

[Ronald R.]

Re: 1970 Corvette LT1/ZR1 Radiator hoses

I would never have noticed it but the intake is not 1970, and there are subtle differences on the water pump. I STILL DON'T KNOW WHAT HOSE I NEED TO USE!!!!!

[Joe L.]

Re: 1970 Corvette LT1/ZR1 Radiator hoses

I would never have noticed it but the intake is not 1970, and there are subtle differences on the water pump. I STILL DON'T KNOW WHAT HOSE I NEED TO USE!!!!!

Ronald------


I don't, either. Sorry for the part numbers I provided earlier.

[Ronald R.]

Re: 1970 Corvette LT1/ZR1 Radiator hoses

The core support on the ZR1 was Modified at the factory which shifted the radiator to one side. I can't think of a reason they moved the radiator other than hose misfit. This coupled with the tilted connection on the top hose must have complicated the assembly process. The top hose that was on mine is 3906616 and fits well. It appears to have been cut to fit. The bottom hose seems to be in the same position but will verify when I get back to shop. I have found and old supply of hoses and seem to have most of the possibilities available to man! more soon

[Joe L.]

Re: 1970 Corvette LT1/ZR1 Radiator hoses

The core support on the ZR1 was Modified at the factory which shifted the radiator to one side. I can't think of a reason they moved the radiator other than hose misfit. This coupled with the tilted connection on the top hose must have complicated the assembly process. The top hose that was on mine is 3906616 and fits well. It appears to have been cut to fit. The bottom hose seems to be in the same position but will verify when I get back to shop. I have found and old supply of hoses and seem to have most of the possibilities available to man! more soon

Ronald-----


VERY interesting. The GM #3906616 hose replaced GM #3887153 in December, 1966. The 3887153 was the upper hose used for 1966 Corvettes with 427 and K-19. The 3906616 may have been used in PRODUCTION for late cars and, after December, 1966 was the SERVICE hose for the application until it was discontinued without supercession about 10 years ago. The 3906616 also replaced the GM #3906615, the upper hose used for 1966-67 427's without K-19, in February, 1978.

It may very well be that the 3906616 was the upper hose that was used for the 1970 ZR-1 application. Certainly, it was available in the "GM parts bin" at the time.

I'll be very interested to learn what you find out about the lower hose.

[Ronald R.]

Re: 1970 Corvette LT1/ZR1 Radiator hoses

I am certain the correct bottom hose was 3917669 as none of the the other hoses had a chance of fitting. The assy line guy must have discovered that the lower hose connection was directly blocked by the A arm on one side and with the radiator on the other the hose required refitting. He must have installed the hose on the radiator and removed the bottom mounts and shifted the radiator to make the bottom hose fit. This moved the top connection about 2" to the driver side and the 3935466 and the 3946852 hoses were too short. I am certain there was no GM hose or part number available for these 25 cars built in 1970. To the best of my knowledge all of the 1970 ZR1 core supports were modified on the assembly line and it defies logic that GM could have been ready for this screw up and had a hose built and ready to install. A simple modification of a

3906616

big block hose would work. Comments???

for some reason I can't post pictures but will when possible thanks Ronnie