1966 Corvette - F41 Suspension

[Pete L.]

The NCRS Judging Manual for 1966 Corvettes states that only big block 427, 425 hp cars were delivered with F41 suspensions. I trying to obtain hard evidence, such as an original window sticker, that demonstrates that 1966 Corvettes were built and delivered with F41 suspensions when a big block 427, 425 hp engine was not included. In my case, I have a big block 427, 390 hp. I've even heard of small block cars being delivered with F41 suspensions. Any help would be greatly appreciated.

Pete LeClair

NCRS #59996

[Jack M.]

Re: 1966 Corvette - F41 Suspension

Looking at the 1966 Corvette Dealer Order Form that was supplied by JohnZ, I enlarged the F41 section for you to observe.

[Bill M.]

Re: 1966 Corvette - F41 Suspension

from Corvette News Vol. 9 no. 4 1966 model year:

[Mike M.]

Re: 1966 Corvette - F41 Suspension

when i was 66 team leader back in the 90's, the saying at the time was "all 425's were F-41's but not all f-41's were 425's" . mike

[Pete L.]

Re: 1966 Corvette - F41 Suspension

Thanks for the information Bill. I believe NCRS isn't going to accept this unless I find an original window sticker proving this.

[Pete L.]

Re: 1966 Corvette - F41 Suspension

Mike,

That's very interesting. The 66 Team Leader is telling me I need proof that GM offered F41 Suspensions to non 425 hp cars. Any idea of anyone who might have an original 66 window sticker that could help me out? Thanks so much, Pete

[Richard M.]

Re: 1966 Corvette - F41 Suspension

Pete, Did you miss Jack Morocco's post.......Post#2 ?

That seems quite valid to me, and the fact that it came from John makes it even more evident.

Rich

[Bill M.]

Re: 1966 Corvette - F41 Suspension

Pete, Did you miss Jack Morocco's post.......Post#2 ?

That seems quite valid to me, and the fact that it came from John makes it even more evident.

Rich

I agree with Rich. That's the best proof I've seen. There is a document dated 3/16/66 that has F41 available with 425 only. I believe that document is the basis for the NCRS position. The dealer order Jack provided shows that 3/16/66 document invalid for at least part of the 1966 model year.

[David B.]

Re: 1966 Corvette - F41 Suspension

Confidential Chevrolet production records indicate the following:
F-41
Special front & rear
Suspension Equipment
---------------------------
Exc. Units

AA 2,705
AB 0
TOTAL 2,705

This would indicate the option was only installed on one type engine equipped '66 Corvette

[Pete L.]

Re: 1966 Corvette - F41 Suspension

The 1966 Corvette Dealer Order sheet makes it quite clear that you could order an F41 suspension with a 390 or 425 hp car. Thanks to everyone who provided responses. I'm having a tough time getting a good printout of the dealer order form. Could whomever posted it please email me a copy direct. My email is "pete@leclairent.com". You could also text it to me at 970.396.6000. Thanks again,

Pete

[Joe L.]

Re: 1966 Corvette - F41 Suspension

All-------

The 1966 Chevrolet Order Guide dated November 1, 1965 indicates that F-41 suspension was available only with the the 425 hp engine. However, the order form shown by Jack M. above obviously indicates that it could be ordered with either the 390 or 425 hp engines. It could be that the engine prerequisite was changed sometime between 11/1/65 and the time the order form was printed. In any event, as of the time that this order form was in use, a customer could order F-41 and also order the 390 HP engine. This is the actual form that the dealer sent to the zone office. So, if the customer ordered both F-41 and the 390 hp engine, the zone office would have to reject the order if F-41 was, indeed, not available with the 390 hp engine. There certainly was no FUNDAMENTAL reason that F-41 could not have been installed on a 390 hp Corvette (or, any other Corvette for that matter). However, GM generally did limit as a management decision F-41 availability to applications otherwise equipped with SHP, mechanical lifter engines. Management decisions can be changed while reasons of fundamental incompatibility cannot.

Why? Well, my take on it is that they were concerned that folks might just order it without considering the down side consequences. Then, they'd be unhappy with the ride quality of the car. They may have reasoned that folks also ordering a SHP engine would be more savvy regarding F-41 consequences and also actually wanting maximum suspension performance regardless of said consequences.

Quite frankly and in my opinion, anyone that ordered F-41 suspension for a Corvette that was primarily intended to be street driven was absolutely NUTS. I thought so then and I think so now.

By the way and to underscore my opinion of F-41, I have ALL the NOS components [none for sale] to convert a 1963-72 Corvette to F-41 suspension. Would I ever do it? Never. Ever.

[Joe L.]

Re: 1966 Corvette - F41 Suspension

The NCRS Judging Manual for 1966 Corvettes states that only big block 427, 425 hp cars were delivered with F41 suspensions. I trying to obtain hard evidence, such as an original window sticker, that demonstrates that 1966 Corvettes were built and delivered with F41 suspensions when a big block 427, 425 hp engine was not included. In my case, I have a big block 427, 390 hp. I've even heard of small block cars being delivered with F41 suspensions. Any help would be greatly appreciated.

Pete LeClair

NCRS #59996

Pete------


Want a very solid indicator if the car was originally equipped with F-41 suspension? Check the forging numbers on the lower rear shock mount shafts. While it's relatively easy to convert a standard suspension car to F-41, very few folks are aware that the shock mount shafts were different for standard suspension and F-41. The standard suspension shafts will work fine for F-41 so there's no fundamental reason or cue to a "converter" that they also need to be changed.

The presence of the standard suspension shafts is very good evidence that the car has been converted. However, the presence of the F-41 shafts is not proof-positive that the car is an original F-41. That's because the F-41 shafts replaced the standard suspension shafts for SERVICE of all 63+ Corvette applications many years ago. However, there were some difference between the original F-41 shafts and those produced much later.

[Pete L.]

Re: 1966 Corvette - F41 Suspension

Joe,

You have been very helpful and I really appreciate it. That said, I'm still hopeful that I can find a window sticker which documents that at least one 390 hp car was delivered with an F41 suspension. That would be iron clad if I can find such a document.

[Keith B.]

Re: 1966 Corvette - F41 Suspension

Post #11 says your never find that document that you want to see

[Gary B.]

Re: 1966 Corvette - F41 Suspension

... I've even heard of small block cars being delivered with F41 suspensions. Any help would be greatly appreciated.

Pete,

Some people mistakenly use the term F41 rear suspension to refer to the HD rear spring for years other 1966 thru 1969. Perhaps someone was talking about the use of the HD rear spring on, for example, a '64 or '74-'82 when the HD rear spring was available with small block engines.

Gary