1970 454 Two Radiator Caps
Thread Starter
Instructor
Joined: Nov 2018
Posts: 193
Likes: 70
From: Chicago
1970 454 Two Radiator Caps
I have 1970 with its original 454, AC and a 4-speed. The car has the thin expansion tank with a radiator cap, due to the car having AC. However, the radiator that is in the car (probably not original) also has a radiator cap. Would I just put AC-15 caps on both? Will this combo of two radiator caps cause any issues?
Thank you for the help.
Thank you for the help.
Racer
Joined: Jul 2018
Posts: 331
Likes: 123
From: Sandusky, OH
Nope! My ‘71 350 had an expansion tank and a copper/brass replacement radiator. Two 15lb caps; no problem. Except I did have a NAPA cap fall apart after a year. Just leaked from that cap, which was annoying.
Steve O.
Steve O.
Race Director
Joined: May 2006
Posts: 18,737
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I have 1970 with its original 454, AC and a 4-speed. The car has the thin expansion tank with a radiator cap, due to the car having AC. However, the radiator that is in the car (probably not original) also has a radiator cap. Would I just put AC-15 caps on both? Will this combo of two radiator caps cause any issues?
Thank you for the help.
Thank you for the help.
https://bobdrake.com/products/1937-4...BoCd10QAvD_BwE
Le Mans Master
Joined: Jan 2001
Posts: 6,743
Likes: 1,385
I have 2 caps on my 68.
1 on the expansion tank (functional) and one on the radiator (just a cap).
I gutted the cap on the radiator so it is really just a cap and does NOT perform any pressure release function. Been like that for 20+ years (I'd have to check). My radiator is an aluminum radiator from summit because it was the biggest relatively inexpensive one I could squeeze into the space on my 68. That original 68 Radiator was a little bitty thing. I figured if I ruined it then it would not be an expensive mistake...but it has worked wonderfully.
1 on the expansion tank (functional) and one on the radiator (just a cap).
I gutted the cap on the radiator so it is really just a cap and does NOT perform any pressure release function. Been like that for 20+ years (I'd have to check). My radiator is an aluminum radiator from summit because it was the biggest relatively inexpensive one I could squeeze into the space on my 68. That original 68 Radiator was a little bitty thing. I figured if I ruined it then it would not be an expensive mistake...but it has worked wonderfully.
I have 1970 with its original 454, AC and a 4-speed. The car has the thin expansion tank with a radiator cap, due to the car having AC. However, the radiator that is in the car (probably not original) also has a radiator cap. Would I just put AC-15 caps on both? Will this combo of two radiator caps cause any issues?
Thank you for the help.
Thank you for the help.
Last edited by carriljc; May 5, 2024 at 10:17 PM.
1967 Pedal Car Champion
Joined: Mar 2020
Posts: 9,137
Likes: 4,248
From: US-PNW
You are right in thinking the radiator shouldn't have a cap. Big blocks ('69-'72) had an expansion tank did so did not have a standard radiator neck. (not sure about '73 & '74 bb) The '66-'68 427s did not have expansion tanks so had the cap on the radiator.
