Fuel Injection 1964 & 1965

[Bruce B.]

On the 7017380 units which were used in both 64 and 65 are thier any differences between the 2 years models?
The only difference I have found is a minor change on the fastener for the shield on the rear of the main diaphragm.
Air and fuel meter numbers are the same.
On the 380 unit did Rochester start the serial number at 0001 for 1965 or did they continue with the number series from 1964?
I am going to look at a unit to buy and any info would be helpful.
Thanks

[Dan H.]

Re: Fuel Injection 1964 & 1965

Hi Bruce, in addition to the fuel bowl stud/baffle, they added a 'anti splash' fine mesh screen to the return port from the spill valve to the float bowl. This started sometime in mid 64, Noland Adams gives some details in his C2 book. The numbers are sequential for all 380 units from 64 to 65. Some details are also included in the 65 shop manual FI section.
Dan

[Wayne M.]

Re: Fuel Injection 1964 & 1965

......On the 380 unit did Rochester start the serial number at 0001 for 1965 or did they continue with the number series from 1964? .....

There are some real F.I. experts on this board [I'm not one ] but I vote that the 380 series for 1965 continued the count from 1964. I saw an original Canadian '64 VIN 014732, with it's VIN derivative stamped on the front plenum, as Noland shows. Its 380 series tag was number 2087.

I used to own the original unit from '65 VIN 06114, (another Canadian car) and it's tag was serial 2642.

[Bruce B.]

Re: Fuel Injection 1964 & 1965

Thanks for the info guys.

I went and looked at the unit this morning.
It was a 380 from probably early 64.
My problem was that it had no numbers cast or stamped on the air or fuel meter. The air meter had a "G" cast on the top flange against the plenum.
There was no sign of a vin ever being stamped anyplace on the unit.
Possibly a service replacement FI unit?
I did not buy it.

[Mike L.]

Re: Fuel Injection 1964 & 1965

380 were NEVER used on a early 1964 Corvette, around 3rd or 4th week of October they went to a 380 unit

[Mike M.]

Re: Fuel Injection 1964 & 1965

Thanks for the info guys.

I went and looked at the unit this morning.
It was a 380 from probably early 64.
My problem was that it had no numbers cast or stamped on the air or fuel meter. The air meter had a "G" cast on the top flange against the plenum.
There was no sign of a vin ever being stamped anyplace on the unit.
Possibly a service replacement FI unit?
I did not buy it.

bruce: there were a few 65 FI vets that did not have the car's vin # stamped on the plenum. as i recall, they were january 65 vets. over the counter plenums wouldn't have a vin stamping either.mike

[John D.]

Re: Fuel Injection 1964 & 1965

Bruce, In looking for a 7380 unit I wouldn't be too concerned about the serial number on the tag and would not worry about a vin# stamped on the plenum.
One weakness in the 7380 units is that so many of them have cracked plenum legs. The weakness may have been from the owner rather than a defect from RP. IF you find a nice 7380 with good castings it would be worth buying. The internal parts can be replaced. It is next to impossible to have a plenum repaired so that the repair goes undetected.
Some of the early 7380 units had left over 63 air meters. Those air meters will have a slotted plug where the 90 degree fitting went for the VA tube on a 63. Now I am not saying all early 7380 units had these but "some' did.
Tip to know if your early 63 7380 unit with a slotted plug is real or hobbiest created. The slotted plug is there for decoration on the real deal. Meaning that it just covers up a vacuum hole that was never drilled into the bore. You would run the unit without the fitting.

There were two enrichment diaphragms used on the 7380's. That's the small cover on the front of the fuel bowl. Cover held on with 54 scews.
Most 64's used the same cover as say a late 57 to 61 FI. A lot of the 65's used a different cover. One that looked like a 63 cover except the hole was not drilled for a cranking signal valve. Now there was no exact science on this though.
7380 units used two different size nozzles.
A lot of the 64 units used "Y" nozzles.. Most of the 65 units used "X" nozzles.
Look in Noland Adams book for info on when the float baffle was installed on a 64. Rather late in the year. I am not going to quote a number. I think the 5th edition has this as the14-16K range. I forget.
At around the same time the float baffle was installed in the 7380 units the front of the 64 plenums were stamped. Stamping was on the boss that hold the chrome balance tube clamp. Reportedly late in the year the 64 units may have been stamped in the right rear like some of the 65's were.
Always put a 7380 unit on a surface plate to make sure the plenum legs are not warped. If so that must be corrected. Don't over torgue those plenums. When asked what the torgue is my answer is "there isn't any".
Meaning just use small wrenches and gently snug the plenum to the baseplate.Doesn't take much to crack a plenum leg.
No lock washers were used under the 8 nuts.

According to info provided by Jon Blanchette around 1975 there were 2144 production 7380 units in 64-65. He said there were only 67 service units-sold over the counter.
Frank Sciabica of RP said the 67 number was not correct by a long shot. But that's not really important.
The 7380 FI unit was the best one Rochester Products made. Correctly restored it's a very reliable unit. Even more than my favorite 63 FI.

You didn't ask Bruce but here's some trivia about 7380 plenums. They were used on over the counter 63 FI units. Jorjorian and Hanson said that if you didn't buy your NOS unit in 1963 from Chevy you most likely got one that was assembled by RP using the later style plenum. I have only seen one NOS 63 FI unit that had a 63 plenum. The rest had/have the later plenum.

[Bruce B.]

Re: Fuel Injection 1964 & 1965

Guys,

Thanks for the information.

Bruce B

[Doug L.]

Re: Fuel Injection 1964 & 1965

My December 1963 built '64 corvette has the 7380 unit without the VIN number on the plenum.