1958 270hp beginning build date

[Jack C.]

According to the NCRS 1958 judging manual and Alan Colvin's "Chevrolet by the numbers" book the RPO 469 270hp engine option was not available until approximately January 20, 1958. However, according to Noland Adam's restoration and technical guide Vol. 1 the RPO 469 high hp is mentioned multiple time regarding exhaust system, tachometer, and especially the carburetors used.

On page 272 he states: "The first carburetors used on 1958 Corvettes with RPO 469 were the same as used on the 1957 RPO 469 245-horsepower engine. They were parts number 3744002, a Carter WCFB 2626S in front, and 3744004, a Carter WCFB 2627S in the rear. These carburetors were used on all 1958 RPO 469 engines regardless of horsepower until AIM date 12-6-57, about when serial number J58S101600 was assembled. After that date, the AIM called for all 1958-60 RPO 469 engines to receive the same carburetors used on 1957 Corvettes with RPO 469. They are: for the 245-horsepower, front carburetor part number 3744002, a Carter WCFB 2626S, rear carburetor part number 3744004, a Carter WCFB 2627S, for the 270-horsepower, front carburetor part number 3741089, a Carter WCFB 2613S, rear carburetor part number 3741090, a Carter WCFB 2614S.

Based on what Nolan states in his book it would appear that the 270-hp RPO 469 option was available for all of the 1958 production year and that in early December of 1957 they simply changed the carburetors used on the higher horsepower configuration.

Can someone explain why the NCRS judging manual and Alan Colvin state that the 270-horsepower RPO 469 option was not available until approximately January 20, 1958?

Thank you.

[Gene B.]

Re: 1958 270hp beginning build date

My car was built on 2-3-58. I asked and was told by the regional meet judges that they even would question a car with an engine build date of January 21, 1958 if it had a 270 HP set up.

I have had my car judged at a regional. It has a 245 HP setup, but it also has a high rev tach. I was told by judges that that was acceptable, since they believe that cars were produced with high rev tachs with the idea that the car was to have 270 HP carbs, but that they were not released until sometime in late January. Even though my engine has a casting date of 1-17-8, I was told that if it had been configured with 270 HP carbs they would question whether that was original.

I know that does not anwser your question, but it is consistant with the JM. I suggest contact Tim Mickey. He may have an anwser for you.

[Jack C.]

Re: 1958 270hp beginning build date

Gene,
Thanks for the feedback. Doesn't make any sense to me that the 270hp option that was available on the '57 would not be available on the '58 until half way through the production year. My assumption is the judges didn't give you any specific reason as to why the judging manual states that option wasn't available until approximately January 21, 1958?

Do you know if your car was originally built with the high rev tach? And is it driven off the generator? My understanding is that the high rev tach had different interal gears depending on if it was distributor or generator driven and the two tach had different part numbers ink stamped on the back of the tach along with the assembly date. If that information is still on your's then you should be able to determine what application is was originally intended for.

I'll keep digging and let you know if I unearth anything new.

[Gene B.]

Re: 1958 270 hp beginning build date

I don't recall even looking at the specific date on the tach when I pulled it to restore the cluster. I am pretty sure it was original, since it had the same aging to the face as the rest of the guages. I know the back of the cluster had a Jan 58 inked stamped. I can look to see if the is a date on the teach. I will let you know if I can find one.

Gene

[Gene B.]

Re: 1958 270 hp beginning build date

Sorry it is driven off the generator.

Gene