1972 Fan Shroud and Extension

[Jeff B.]

I have a 1972 LT-1 late June build car. I am assuming that it has it's original radiator shroud and extension (part number 3956109 for the shroud and 3956118 for the extension - both embossed on each piece). The 3 original mounting holes to attach the extension do not line up for some reason (the T-nuts are in place)? Since the mismatched holes- the extension was held on by 3 large head self tapping screws when I pulled it apart.
I read somewhere that some of the 6118 extensions were made wrong. Any other experience? Would the factory have done this?

[Joe L.]

Re: 1972 Fan Shroud and Extension

I have a 1972 LT-1 late June build car. I am assuming that it has it's original radiator shroud and extension (part number 3956109 for the shroud and 3956118 for the extension - both embossed on each piece). The 3 original mounting holes to attach the extension do not line up for some reason (the T-nuts are in place)? Since the mismatched holes- the extension was held on by 3 large head self tapping screws when I pulled it apart.
I read somewhere that some of the 6118 extensions were made wrong. Any other experience? Would the factory have done this?

Jeff-----


I think it's very possible this was done at St. Louis. I have found that many of these 69+ shroud extensions, small block and big block, fit very poorly.

[Jeff B.]

Re: 1972 Fan Shroud and Extension

Joe,
Thanks for the reply. Do you think I should reassemble like I found it with the sheet metal screws? I hate to drill new holes- the extension will have a total of three for each attaching point if I do this.
Will I lose points due to these fasteners when I have the car judged?

Jeff

[Jack H.]

Re: 1972 Fan Shroud and Extension

I have a factory original fan shroud on my '71 SB A/C car with a reproduction extension. The extension fit POORLY requiring me to shave material from it to force the fit and achieve an alignment of the mounting holes.

I wrote that off to 'slop' in the reproduction extension part's manufactured geometry. The FEW factory original cars I've seen that still retain their original shroud and mating extension align pretty well...

But, finding an original car with both shroud and extension still intact is rather rare. Most mechanics and/or prior owners discarded the extension when they did an R&R job because they found the extension did little to enhance air flow AND they discovered the removal of the extension did NOT allow them to pull the shroud critical components still installed (hood on, radiator/core in final rearward tilted position, fan/clutch installed on the water pump)...

[Brad M.]

Re: 1972 Fan Shroud and Extension

Jeff,

My 71 Lt-1 has the situation. It had only the two outer bolts fastened and the bottom center hole was not bolted on when I got the car.

At one point, I found a Corvette parts dealer who had an NOS shroud and NOS extension and it also had the same alignment problem.

I chose to drill an extra hole in my shroud at the bottom area and filled in the original hole with some fiberglass. I do not find it to be noticeable on the car. I had trouble with the fan wanting to nick the shroud extension before I made the extra hole. If it were not for that, I probably would have left it alone.