rick1500

I'm trying to figure out which ID number my Q-Jet should have for my 1970 350-350, 4-speed. The car was built in July of 1970. From this page, there seems to be only 2 possibilities:

http://www.corvetteactioncenter.com/...1970/70id.html

Rochester Q-jet #7040207: 350ci, 350hp (manual transmission)

-or-

Rochester Q-jet #7040507: 350ci, 350hp (manual transmission, evaporative emission controls)

Where the only difference is the evap. emission controls. Does anyone know which I should have? Thanks!

rick1500

Sorry, I meant to post in C3 Tech. I just re-posted there...please reply to this thread instead:

http://forums.corvetteforum.com/show....php?t=1869678


Can a moderator please delete this one? Thanks!

GD70

The evap carb was for California vettes only I believe. Others may know better.
Glenn

RMVette

The Q-Jets are identified by the numbers that you list and they are stamped on the float bowl casting on the drivers side. The identification number breaks down as this:

As an example 7040207 represents:

70 = All Rochester products were identified by a "70" or "170". The number "70" was for up to 1976 cars, the number "170" was used after 1976.

40 = the year, in this case 1970.

2 = 49 state carb (a 5 in this spot represents a California or high altitude car).

0 = Chevy division

7 = Manual transmission (even numbers were automatics, odd numbers were manuals).

A little more trivia if you want...

The 7040207 carb has:

1) A number "76" main jets
2) A number 44 main rods
3) A number 7029862 spring
4) A "BA" secondary rods

All of the numbers above are the same for both carb numbers you listed. So if your car didn't come from California, then you have a 7040207 carb.

I hope this helps some. I also own a L46 (350/350) with a build date of June and with 4-speed so I've been through this during my restoration! Your car is in the last build month! (VIN numbers from 14285 to 17316).

Good luck!