Underhood clearance issues '75 Corvette
Thread Starter
Heel & Toe
Joined: Jun 2017
Posts: 16
Likes: 0
From: Pittsburgh, PA
Underhood clearance issues '75 Corvette
I am considering changing the intake and carburetor on my '75. I'd like to go to an Edelbrock 7501 Air Gap with an AVS2 650 with electric choke. From what I've seen on the internet, my under hood clearance is a little more than the big block hood that is on the '70 LT-1.
Does anyone know the carb pad height of the Winters Foundry intake that is was on the LT-1 engine? Chevrolet Performance offers a ZZ4 intake Pt# 10185063 which they state is 1/2" lower than the original LT-1 intake, but no numbers are given as a reference. I sent an inquiry to Summit regarding the 10185063 intake and the response was that the carb pad front (A) height was 3.6" and the rear (B) height was 5" which after doing the math comes in at 4.3" at the pad center line. If that information is correct the original LT-1 Winters intake should be approximately 4.8". If this all works out, I would like to use the drop base air cleaner assembly that came on the '70 LT-1.
This air cleaner would need a little bit of modification to clear the electric choke on the AVS2 carburetor.
Any information is appreciated.
Best Regards,.
billt75
Does anyone know the carb pad height of the Winters Foundry intake that is was on the LT-1 engine? Chevrolet Performance offers a ZZ4 intake Pt# 10185063 which they state is 1/2" lower than the original LT-1 intake, but no numbers are given as a reference. I sent an inquiry to Summit regarding the 10185063 intake and the response was that the carb pad front (A) height was 3.6" and the rear (B) height was 5" which after doing the math comes in at 4.3" at the pad center line. If that information is correct the original LT-1 Winters intake should be approximately 4.8". If this all works out, I would like to use the drop base air cleaner assembly that came on the '70 LT-1.
This air cleaner would need a little bit of modification to clear the electric choke on the AVS2 carburetor.
Any information is appreciated.
Best Regards,.
billt75
Melting Slicks
Joined: Apr 2021
Posts: 2,706
Likes: 2,151
From: Minnesota
You shouldn’t run into any clearance issues with that setup. Although if your car still has the original Quadrajet the last thing you want to do is replace it with an Edelbrock/Carter AFB. A well set up and tuned Quadrajet with an Edelbrock 2101 intake would be a superior option IMO, and you won’t run into any clearance issues with that either.
Thread Starter
Heel & Toe
Joined: Jun 2017
Posts: 16
Likes: 0
From: Pittsburgh, PA
Thank you for your response.
I actually have two Quadrajets, the 800 CFM that came on the car and a 750 CFM that was a service part for a 1970 Olds 442, non W30. I've been told by one Q-jet rebuilder that the vintage of both Quadrajets, 1970 & 1975, are not desirable for rebuilding. I don't want to name the individual in this post, but if you have any suggestions let me know.
The original L48 engine has been built into a 383 stroker. The only part of the original engine that remains is the block. When we were trying to correct some issues with the current carb, a Quick Fuel HR series 780 VS, we discovered that the 2101 intake was a bit wonky (technical term). The area above the intake ports is not the same thickness one side to the other and it is very difficult to gasket.
There is nothing like the sound of a Quadrajet when you nail it.
Best Regard,
billt75
I actually have two Quadrajets, the 800 CFM that came on the car and a 750 CFM that was a service part for a 1970 Olds 442, non W30. I've been told by one Q-jet rebuilder that the vintage of both Quadrajets, 1970 & 1975, are not desirable for rebuilding. I don't want to name the individual in this post, but if you have any suggestions let me know.
The original L48 engine has been built into a 383 stroker. The only part of the original engine that remains is the block. When we were trying to correct some issues with the current carb, a Quick Fuel HR series 780 VS, we discovered that the 2101 intake was a bit wonky (technical term). The area above the intake ports is not the same thickness one side to the other and it is very difficult to gasket.
There is nothing like the sound of a Quadrajet when you nail it.
Best Regard,
billt75
Last edited by billt75; Oct 2, 2024 at 07:38 AM. Reason: removed phone number
Melting Slicks
Joined: Apr 2021
Posts: 2,706
Likes: 2,151
From: Minnesota
I take it the two Quadrajets you have are commercially rebuilt carbs? That’s what would make them the most difficult to rebuild and set up correctly. I’m not sure who your carb expert is, but if you haven’t seen Lars’s threads on the forum here they’re all worth a read.
You do mention in your other threads that your 383 is good for 510 horsepower. Do you have more information on the heads and camshaft you used? Perhaps a Quadrajet or Edelbrock wouldn’t be optimal with the amount of vacuum the engine is making. There are a number of mechanical secondary Holleys that would work better on your application.
You do mention in your other threads that your 383 is good for 510 horsepower. Do you have more information on the heads and camshaft you used? Perhaps a Quadrajet or Edelbrock wouldn’t be optimal with the amount of vacuum the engine is making. There are a number of mechanical secondary Holleys that would work better on your application.
Thread Starter
Heel & Toe
Joined: Jun 2017
Posts: 16
Likes: 0
From: Pittsburgh, PA
Pierson,
Both of my Quadrajets are in the original condition and each has approximately 5,000 miles of use.
My car is a '75 mildly restomoded survivor with a 4 speed and A/C. The next time out of the garage it will turn 12,000 miles.
The engine has all forged internals, Brodix IK200 heads with 70cc combustion chamgers and a CR of 10.13. The cam is a Comp roller, 12-432-8, duration at .050" 230 intake.236 exhaust, LSA 110 degrees. Manifold vacuum is 13" Hg @ 900 RPM. The 510hp is at the flywheel from a computer simulated dyno program. I figure I've got approximately 400 to 425 hp at the wheels. The B-W Super T10 has a 2.64 1st gear with a 3.36 rear. The exhaust is 1-3/4" shorty headers into the C2 chambered side exhaust behind the '69 covers. I'm not really looking for a double pumper carb since I don't race the car. A couple of engine builders I've talked with feel that the 7501 Air Gap and the 650 AVS2 is a great combination for the street.
Let me know your thoughts.
All the best,
billt75
Both of my Quadrajets are in the original condition and each has approximately 5,000 miles of use.
My car is a '75 mildly restomoded survivor with a 4 speed and A/C. The next time out of the garage it will turn 12,000 miles.
The engine has all forged internals, Brodix IK200 heads with 70cc combustion chamgers and a CR of 10.13. The cam is a Comp roller, 12-432-8, duration at .050" 230 intake.236 exhaust, LSA 110 degrees. Manifold vacuum is 13" Hg @ 900 RPM. The 510hp is at the flywheel from a computer simulated dyno program. I figure I've got approximately 400 to 425 hp at the wheels. The B-W Super T10 has a 2.64 1st gear with a 3.36 rear. The exhaust is 1-3/4" shorty headers into the C2 chambered side exhaust behind the '69 covers. I'm not really looking for a double pumper carb since I don't race the car. A couple of engine builders I've talked with feel that the 7501 Air Gap and the 650 AVS2 is a great combination for the street.
Let me know your thoughts.
All the best,
billt75
Last edited by billt75; Oct 2, 2024 at 10:18 AM. Reason: added information
Thread Starter
Heel & Toe
Joined: Jun 2017
Posts: 16
Likes: 0
From: Pittsburgh, PA
Barry,
Thank you for the pictures.
Please confirm that your air cleaner is the original LT-1 assembly as I can't see the breather tube that exits from the bottom of the passenger side in the pictures you supplied. Also, if possible, please advise if the air cleaner bottom has a 2" dropped base.
Your help is appreciated.
Best regards,
billt75
Thank you for the pictures.
Please confirm that your air cleaner is the original LT-1 assembly as I can't see the breather tube that exits from the bottom of the passenger side in the pictures you supplied. Also, if possible, please advise if the air cleaner bottom has a 2" dropped base.
Your help is appreciated.
Best regards,
billt75
