fuel injection switch 375R to 380?

[Matt L.]

in my early build oct 28 64 fuel car i have a 375R. when did they switch to 380 unit. i looked at a complete late nov 20-28 engine and it was a 380 unit. just curious. it was less than 30 days apart.
take care,
matt

[John M.]

Re: fuel injection switch 375R to 380?

Matt,
I think Jim Gessner, Drew Papsun or John Degregory could probably answer that question. Maybe one will chime in or maybe there's something in Nolans book?

[Mike L.]

Re: fuel injection switch 375R to 380?

I've started watching and studing the 1964 fuel injection change over many years ago and to my best understanding the 375R unit was used until the beginning of January 1964. At this time they went to a 380 unit. I have heard form a good source that not many 375R units went on production cars. There were some service 375R units used for a very short time. I have a 375R unit on my early 64 works great.

[Matt L.]

Re: fuel injection switch 375R to 380?

hi mike!
the engine i almost bought was a complete engine, fuel injection to oil pan that came out of a totaled 64 car. it was late nov and assembly dated engine. it had the 380 unit on it. i wanted to buy it until i learned it was a 380 unit instead of the correct 375R. if i'm in that area again,i'll get some pics for all of us to compare and share.

[Michael H.]

Re: fuel injection switch 375R to 380?

I've started watching and studing the 1964 fuel injection change over many years ago and to my best understanding the 375R unit was used until the beginning of January 1964. At this time they went to a 380 unit. I have heard form a good source that not many 375R units went on production cars. There were some service 375R units used for a very short time. I have a 375R unit on my early 64 works great.

If your 375R FI unit is original, I have a question. Does the vacuum advance plumbing (hose/pipe and fitting) connect to the top of the air meter, just like a 375 FI unit for 63? Or does it connect to a fitting at the rear of the plenum?
I think it should be connected to the air meter, just like a 63, but I'm not sure.
Thanks.

By the way, I owned a 64 coupe, # 5297, an all original unrestored and untouched 4000 mile car, and it definitely had it's original 380 FI unit.

[Joseph S.]

Re: fuel injection switch 375R to 380?

If there were only 100 or os 375R units put on cars at the factory, running them out to serial number 8000 (Dec 31) does not make logical sense to me. I would expect that the 100 pieces would be done by the end of October.

[John D.]

Re: fuel injection switch 375R to 380?

This is a difficult question that I have been pondering with an open mind for many years.
Here is a good reference for you. An old time NCRS member named Leo Ensz is the original owner of a NOV 63. I am not going to give you the exact serial number of the car but will say it's in the 4800 range.
Unit: 7017380 Serial number in the 1100 range.
Now this is not to say that every early 64 after Leo's car had/has a 7017380 unit because that just isn't true.
I have proof that there was a time that BOTH FI units were used at St. Louis. The left over 63 units: 7017375R and the early 7017380 FI's.
I can appreciate some of you not believing that.
I think it would be easier to ask this question. About when was the last 7017375R unit used on a 64 Corvette??? Answer may be late Dec 63 early Jan 64.
The last few years I have been restoring a high number of 64 FI's. I really haven't learned anything new except for this one big discovery. I think I knew this before but I forget stuff.

I used to think that ALL the early 7017380 FI units had left over 7375 or 7375R air meters. Ones that had the 1/8" slotted pipe plug on top where the typical distributor vacuum advance 90 degree fitting goes. Hanson asked about that (I think).
Well the answer to the above is that I was wrong/incorrect.
I have seen early 7380 FI units with low serial numbers on the ID tag that do NOT have this slotted plug. And I have seen a lot of them that in fact do have this plug.
Now I am not trying to sell you a cheap print/poster but if you want to see a very early 74 7017380 FI unit go on ebay right now and type in Fuel Injection Art. Click on the 64-65 print and look closely at the air meter and see this slotted plug.

Where did you get the info on the 100 or so units from the factory??? tHe 7017375R units. I don't think so. But you did say "or so". The number was much higher than that.
One time I restored a late Nov 63 that was easy to remember the number. Serial of the FI was 3999. 7017375R. Real deal FI car.
Now go look at Leo's unit info.
Frank Scibica of RP told me years ago when I was totally confused about this same exact question. Frank said this to me. JD we were trying to unload the 7017375R units and shipped as many as possible as the bean counters were upset with us (RP). But they covered their trail by shipping both models of units at the same time.
Dave Cardina has an early Jan 64. Dave bought the car new but it changed hands a few times and he bought it back. Dave has pics of his car when it was brand new. 7017380 unit.
Another friend has an original 64 built the same time as Dave's. 7017375R. Go figure.

[John D.]

Re: fuel injection switch 375R to 380?

Michael and others. The 7017375 and '7375R units are 100%identical in appearance. The only differences are the nozzles, the calibration, and the enrichement diaphragm spring (not seen) because of the 2 different camshafts. JD

[Michael H.]

Re: fuel injection switch 375R to 380?

This is a difficult question that I have been pondering with an open mind for many years.
Here is a good reference for you. An old time NCRS member named Leo Ensz is the original owner of a NOV 63. I am not going to give you the exact serial number of the car but will say it's in the 4800 range.
Unit: 7017380 Serial number in the 1100 range.
Now this is not to say that every early 64 after Leo's car had/has a 7017380 unit because that just isn't true.
I have proof that there was a time that BOTH FI units were used at St. Louis. The left over 63 units: 7017375R and the early 7017380 FI's.
I can appreciate some of you not believing that.
I think it would be easier to ask this question. About when was the last 7017375R unit used on a 64 Corvette??? Answer may be late Dec 63 early Jan 64.
The last few years I have been restoring a high number of 64 FI's. I really haven't learned anything new except for this one big discovery. I think I knew this before but I forget stuff.

I used to think that ALL the early 7017380 FI units had left over 7375 or 7375R air meters. Ones that had the 1/8" slotted pipe plug on top where the typical distributor vacuum advance 90 degree fitting goes. Hanson asked about that (I think).
Well the answer to the above is that I was wrong/incorrect.
I have seen early 7380 FI units with low serial numbers on the ID tag that do NOT have this slotted plug. And I have seen a lot of them that in fact do have this plug.
Now I am not trying to sell you a cheap print/poster but if you want to see a very early 74 7017380 FI unit go on ebay right now and type in Fuel Injection Art. Click on the 64-65 print and look closely at the air meter and see this slotted plug.

Where did you get the info on the 100 or so units from the factory??? tHe 7017375R units. I don't think so. But you did say "or so". The number was much higher than that.
One time I restored a late Nov 63 that was easy to remember the number. Serial of the FI was 3999. 7017375R. Real deal FI car.
Now go look at Leo's unit info.
Frank Scibica of RP told me years ago when I was totally confused about this same exact question. Frank said this to me. JD we were trying to unload the 7017375R units and shipped as many as possible as the bean counters were upset with us (RP). But they covered their trail by shipping both models of units at the same time.
Dave Cardina has an early Jan 64. Dave bought the car new but it changed hands a few times and he bought it back. Dave has pics of his car when it was brand new. 7017380 unit.
Another friend has an original 64 built the same time as Dave's. 7017375R. Go figure.

I don't think I agree with most of that.

You mention that you "have proof" that 375R units were used through November 63. What is that proof?

[Matt L.]

Re: fuel injection switch 375R to 380?

hi john!
thank you for all your knowledge. john, you are the one who saved me from making a very expensive mistake when i was considering that other engine. you pointed out i needed the 375R. i really appreciate that. that engine is still for sale. $18,500 if anyone is interested. complete fuel injection to pan. pulleys,brackets,manifolds,dist,etc. COMPLETE. thats why i was so interested. no need to hunt for months like i had to for my engine. but it all would've been wrong if i bought it. wrong date codes and wrong 380 unit. thank you john.
take care,
matt

[Mike L.]

Re: fuel injection switch 375R to 380?

Michael, the vacum advance plumbing does connect to the top and run to the air meter. I do believe it correct because the unit was never off the car till I gave it to Gail P. to rebuild. (RIP Gail you were a great person).

[Mike L.]

Re: fuel injection switch 375R to 380?

Just got home from work(snowing like ****) in New England. Thinking what has been said about real cars with FI, and looking over my 64 survey the change over from 375R to 380 units could have been around end of Nov 63 OR sometime mid Dec. 63. I have cars #6302 and #6425 both with a 380 units, that would put it mid Dec. 63. My own 64 car with a 375R unit has serial number 3957.

[Michael H.]

Re: fuel injection switch 375R to 380?

Just got home from work(snowing like ****) in New England. Thinking what has been said about real cars with FI, and looking over my 64 survey the change over from 375R to 380 units could have been around end of Nov 63 OR sometime mid Dec. 63. I have cars #6302 and #6425 both with a 380 units, that would put it mid Dec. 63. My own 64 car with a 375R unit has serial number 3957.

Add 64 #5297 to your list of cars with a 7017380 FI unit. I don't remember the time/month of build.

I doubt any cars originally equipped with a 7017375R would have been built after 5297.

[Matt L.]

Re: fuel injection switch 375R to 380?

hi mike, when was your 3957 built? my 3760 is real close to yours.just curiuos.
thanks mike.

[Dino L.]

Re: fuel injection switch 375R to 380?

Matt, my VIN 38XX 64 was built Oct 29, 1963