[C2] L68 or L36?
02-24-2020, 01:21 AM
#1
L68 or L36?
Our family recently acquired a yellow 1967 Air Conditioned 427 4 speed corvette. The original 427 has since been replaced with a 1970 spec LS6 crate engine. As the car is Air Conditioned, clearly the only original engine options are the L36 390hp or the L68 400hp Tri-Power. As the 390hp cars were Holley equipped, the fuel lines on the frame do not identify the original engine. Besides having a tank sticker Im hoping someone can tell me if there are any other parts, wiring, firewall holes, linkage or unused fasteners etc that might tell me what motor it was originally equipped with. Help!!
02-24-2020, 04:47 AM
#2
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Nope. Not without the tank sticker or POP will you know for sure
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02-26-2020, 08:26 PM
#3
There is one way. If your registration still carries the exact curb weight for your specific car, you can figure it out by adding up the weight of the options on your car. L68 was recorded as weighing 64 pounds less than the L36. Why? Who knows, as there wasn't that much difference between the cast and aluminum intake manifold weights.
Maybe a 2nd way, not sure as I’m not in my office. Since your car is an A/C car, check your AIM to see if the adjusting bracket that goes over the passenger valve cover is the same for L36 and L68. The piece of the bracket that I’m referring to is the one that mounts on the intake manifold with 2 bolts, and spans over #2 & #4 intake ports. Maybe they were different for the L68 intake manifold, not sure. I remember dealing with some issue with that bracket before though.
If not, you’re on your own looking for the original owner.... 🥺
Maybe a 2nd way, not sure as I’m not in my office. Since your car is an A/C car, check your AIM to see if the adjusting bracket that goes over the passenger valve cover is the same for L36 and L68. The piece of the bracket that I’m referring to is the one that mounts on the intake manifold with 2 bolts, and spans over #2 & #4 intake ports. Maybe they were different for the L68 intake manifold, not sure. I remember dealing with some issue with that bracket before though.
If not, you’re on your own looking for the original owner.... 🥺
Last edited by OldCorvetter; 02-26-2020 at 08:27 PM.
02-26-2020, 08:29 PM
#4
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There is one way. If your registration still carries the exact curb weight for your specific car, you can figure it out by adding up the weight of the options on your car. L68 was recorded as weighing 64 pounds less than the L36. Why? Who knows, as there wasn't that much difference between the cast and aluminum intake manifold weights.
Maybe a 2nd way, not sure as I’m not in my office. Since your car is an A/C car, check your AIM to see if the adjusting bracket that goes over the passenger valve cover is the same for L36 and L68. The piece of the bracket that I’m referring to is the one that mounts on the intake manifold with 2 bolts, and spans over #2 & #4 intake ports. Maybe they were different for the L68 intake manifold, not sure. I remember dealing with some issue with that bracket before though.
If not, you’re on your own looking for the original owner.... 🥺
Maybe a 2nd way, not sure as I’m not in my office. Since your car is an A/C car, check your AIM to see if the adjusting bracket that goes over the passenger valve cover is the same for L36 and L68. The piece of the bracket that I’m referring to is the one that mounts on the intake manifold with 2 bolts, and spans over #2 & #4 intake ports. Maybe they were different for the L68 intake manifold, not sure. I remember dealing with some issue with that bracket before though.
If not, you’re on your own looking for the original owner.... 🥺
they are the same between the two.
and I disagree about the weight of the bare intakes.
02-26-2020, 09:20 PM
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02-26-2020, 09:33 PM
#6
So I’m not sure what Nowhere Man is disagreeing with. I think 64 pounds difference is weird, and I said so, but that is the stated difference between the 2 engine options add ons (215 lbs vs 151 lbs). So are you disagreeing with the add on weight math? Or are you disagreeing that I think it’s incorrect, which is a double negative that I can’t get my head around? Or are you just agreeing to disagree....? I think I need a beer now. 🤔
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02-27-2020, 09:08 AM
#7
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I was only disagreeing with your statement about the weight difference of the two intakes. When picking them up you can tell very easy.