L58-62 Road Draft Tube 3737028 or optional 3749690 ?????

[David L.]

While looking for other parts in my collection I came across a very nice original road draft tube that I removed from a 1960 Chevrolet Impala many years ago. I tagged it as 57-60 Chev. Pass w/T.G. trans and L58-62 Corvette. Apparently some of the 58-62 Corvette assembly manuals list the tube as GM # 3737028 as well as optional GM # 3749690. My 1962 Corvette AIM lists only GM # 3737028 (Sect. 6, Sheet 11.00).

Can anyone identify which road draft tube in my photos below? Is it 3737028 or 3749690? Also, what is the difference between the 3737028 tube and the 3749690 tube? I assume that there were two different vendors that supplied the road draft tubes to the Chevrolet and Corvette assembly lines.

Dave

[Donald H.]

Re: L58-62 Road Draft Tube 3737028 or optional 3749690 ?????

Here's a picture of the other one, notice that the 90 degree turn is two 45 degree cuts in the tubes. My 1960 AIM list 3737028 and 3749690 also. I think the one I have pictured is 3737028, but can't say that for certain. I believe that the one I have pictures is the earlier version, thus the lower part number. You would know better, did GM used progressive part numbering, i.e. earlier parts have lower numbers?

Road Draft Tube.jpg

[Joe L.]

Re: L58-62 Road Draft Tube 3737028 or optional 3749690 ?????

... did GM used progressive part numbering, i.e. earlier parts have lower numbers?

[ATTACH=CONFIG]48699[/ATTACH]

Donald------


In general and within an assigned part number series, yes.

[Joe L.]

Re: L58-62 Road Draft Tube 3737028 or optional 3749690 ?????

David-----


I cannot find that the 3749690 was ever available in SERVICE. So, apparently, it was a PRODUCTION-only piece.

The GM #3737028 is shown as "2nd design" for 1958 Corvettes. The "1st design" for 1958 Corvettes and used for all 1957 Corvettes is GM # 3726641.

[Mike M.]

Re: L58-62 Road Draft Tube 3737028 or optional 3749690 ?????

i prefer don's crankcase vent tube for 57 corvettes.mike

[Dennis C.]

Re: L58-62 Road Draft Tube 3737028 or optional 3749690 ?????

For 58 - 62 Corvette's, I would be looking for the one in Don's picture.

i always wondered if the one in the first photo might be a later service replacement, or perhaps a passenger car only part?

Dennis

[David L.]

Re: L58-62 Road Draft Tube 3737028 or optional 3749690 ?????

For 58 - 62 Corvette's, I would be looking for the one in Don's picture.

i always wondered if the one in the first photo might be a later service replacement, or perhaps a passenger car only part?

Dennis

Dennis,

The tube in the first photo is from a 1960 Chev. Impala. I found about a half dozen road draft tubes from various Chevrolets back in the 1980's. I sold all the other tubes years ago but this tube apparently got lost in my garage attic. The 3737028 tube was discontinued from service on April 1961 and replaced with GM # 3776635 with the following note: "It may be necessary to cut 6 1/2 inches from lower end of tube assy." In other words, the service tube (GM # 3776635) was much longer than the assembly line tubes. Apparently there were 2 different vendors that supplied the tubes to the assembly line from Late 1958 to 1962, GM # 3737028 and GM # 3749690, and therefore the tubes would be slightly different. The difference appears to be the 90 degree connection at the top end.

Dave

[Bill M.]

Re: L58-62 Road Draft Tube 3737028 or optional 3749690 ?????

This is the original road draft tube from my early '59. Notice the different contour from the '60 Impala in post #1.

[David L.]

Re: L58-62 Road Draft Tube 3737028 or optional 3749690 ?????

Bill,

Your tube looks like the 1st design (GM # 3726641 or maybe optional GM # 3749684) that was used on 56-59 Chevrolets and 56-58 Corvettes according to my research. I would say that your 1st design tube and my 1970 Impala 2nd design tube were made by the same manufacturer since the 90 degree top ends (bolt hole ends) look the same.

It appears that both 1st design and 2nd design tubes were used on L58 and E59 Corvettes.

Dave