4V closed chambered heads on

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Joined
Jan 13, 2012
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1,989
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Location
Washington
My Car
1971 Mach1, 351 Cleveland, Ram Air (not factory), C6 Automatic, AM/8 Track, Bright Red.
I was hesitant to remove my 2V heads and put on 4V closed chambered heads on my 71 M code (previous owner had removed the 4V heads). I had read a lot about the 2V heads having better low end torque and street manners plus the closed chambered 4V needs higher octane fuel. ..but I went ahead and did it.

All I can tell you is I like the performance with the 4V heads MUCH better, I'm running the same 92 octane ethanol free fuel and same carb, there is no pinging, no low end torque issue and I can tell (seat of the pants) there is more power through out the RPM range.

The 2V heads had less than 5,000 miles since their rebuild so I don't think that was an issue in the comparison.

Of course I had to also swap out the intake and exhaust manifolds but I went with the same Edlebrock Performer intake but a 4V verses 2V and swapped out the stock 2V exhaust manifolds with 4V stock manifolds. So it's apples to apples with the exception of 4V verses 2V.

My personal experience - 4V closed chambered heads over 2V heads, yeah baby.

My thanks to Don of OMS for finding me a set of great date matching 4V heads for my 71 M code.

Jim

 
Will my 2v headers bolt up to 4v heads?
Yes they will bolt up - but they will leak at the top around the header bolts.

- Paul

 
I went 4v cc and love them. I am still running the lower speed torque converter so I think I suffer a little off the line but it keeps me from spinning the tires too far. Once I get up in the RPMs it's like a rocket. So much fun.

 
I was hesitant to remove my 2V heads and put on 4V closed chambered heads on my 71 M code (previous owner had removed the 4V heads). I had read a lot about the 2V heads having better low end torque and street manners plus the closed chambered 4V needs higher octane fuel. ..but I went ahead and did it.

All I can tell you is I like the performance with the 4V heads MUCH better, I'm running the same 92 octane ethanol free fuel and same carb, there is no pinging, no low end torque issue and I can tell (seat of the pants) there is more power through out the RPM range.

The 2V heads had less than 5,000 miles since their rebuild so I don't think that was an issue in the comparison.

Of course I had to also swap out the intake and exhaust manifolds but I went with the same Edlebrock Performer intake but a 4V verses 2V and swapped out the stock 2V exhaust manifolds with 4V stock manifolds. So it's apples to apples with the exception of 4V verses 2V.

My personal experience - 4V closed chambered heads over 2V heads, yeah baby.

My thanks to Don of OMS for finding me a set of great date matching 4V heads for my 71 M code.

Jim
Jim, Just wondering where you buy your gas. Been looking for a source in my area.

 
I was hesitant to remove my 2V heads and put on 4V closed chambered heads on my 71 M code (previous owner had removed the 4V heads). I had read a lot about the 2V heads having better low end torque and street manners plus the closed chambered 4V needs higher octane fuel. ..but I went ahead and did it.

All I can tell you is I like the performance with the 4V heads MUCH better, I'm running the same 92 octane ethanol free fuel and same carb, there is no pinging, no low end torque issue and I can tell (seat of the pants) there is more power through out the RPM range.

The 2V heads had less than 5,000 miles since their rebuild so I don't think that was an issue in the comparison.

Of course I had to also swap out the intake and exhaust manifolds but I went with the same Edlebrock Performer intake but a 4V verses 2V and swapped out the stock 2V exhaust manifolds with 4V stock manifolds. So it's apples to apples with the exception of 4V verses 2V.

My personal experience - 4V closed chambered heads over 2V heads, yeah baby.

My thanks to Don of OMS for finding me a set of great date matching 4V heads for my 71 M code.

Jim
Jim, Just wondering where you buy your gas. Been looking for a source in my area.
I get mine on Lilly road in Olympia, here's a complete list of gas stations in WA that offer ethanol free gas. If there list is up to date there are 196, not all of them offer super ethanol free gas though.

http://pure-gas.org/index.jsp?stateprov=WA

 
I was hesitant to remove my 2V heads and put on 4V closed chambered heads on my 71 M code (previous owner had removed the 4V heads). I had read a lot about the 2V heads having better low end torque and street manners plus the closed chambered 4V needs higher octane fuel. ..but I went ahead and did it.

All I can tell you is I like the performance with the 4V heads MUCH better, I'm running the same 92 octane ethanol free fuel and same carb, there is no pinging, no low end torque issue and I can tell (seat of the pants) there is more power through out the RPM range.

The 2V heads had less than 5,000 miles since their rebuild so I don't think that was an issue in the comparison.

Of course I had to also swap out the intake and exhaust manifolds but I went with the same Edlebrock Performer intake but a 4V verses 2V and swapped out the stock 2V exhaust manifolds with 4V stock manifolds. So it's apples to apples with the exception of 4V verses 2V.

My personal experience - 4V closed chambered heads over 2V heads, yeah baby.

My thanks to Don of OMS for finding me a set of great date matching 4V heads for my 71 M code.

Jim
Jim, Just wondering where you buy your gas. Been looking for a source in my area.
I get mine on Lilly road in Olympia, here's a complete list of gas stations in WA that offer ethanol free gas. If there list is up to date there are 196, not all of them offer super ethanol free gas though.

http://pure-gas.org/index.jsp?stateprov=WA
Thx Jim, I see a few in my area and will check them out.

 
How much did you spend? For $2500 (fully set up) you could have bought CHI 3v alum heads and kept your exhaust manifolds...and used a number of real sweet intakes. They flow thru the roof!

 
Awesome Jim!! Sounds like you loving the new combo, I have drove both 2v and 4v clevelands..But drove my 4v for 20 years..I never had a issue with low end power with my 4v heads.

 
How much did you spend? For $2500 (fully set up) you could have bought CHI 3v alum heads and kept your exhaust manifolds...and used a number of real sweet intakes. They flow thru the roof!
I paid $600 for the heads and $800 to have them rebuilt with stainless one piece valves and seats hardened, so $1,400. I did look at alum heads but decided to go the route of keeping it as original as possible, Don was able to find date correct heads for my car. My ram air limits my intake choices. I did stray from originality with the Edelbrock performer 4V intake though. If it wasn't a numbers matching engine, I would have went with a grate engine when I started the project, but to separate them after 43 years would be wrong.

Jim



Awesome Jim!! Sounds like you loving the new combo, I have drove both 2v and 4v clevelands..But drove my 4v for 20 years..I never had a issue with low end power with my 4v heads.
Yep the new combo is better than I expected, you're assurance that there was no drivability issues with 4V cc heads is what convinced me to give it a try.

Jim

 
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Welcome to the real world!:D I think the chevy guys must have started the mith that the 2V heads where better for the street so there 454s would stop getting beat by a small block Ford.:cool:

 
My ford racer mates always say 2v for the first half the track and 4V across the top of the track. Meaning 2V for ETs (to a point of course )and 4V for MPH. I am not saying they are right and they are only speaking about tuff street cars but you hear it a bit from a lot of other ford guys that race too. All as I know is if its blown its goin :p

Not a critism in anyway of either head just passing on some anecdotal comments

 
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Did the shop give you a guesstimate on what your compression ratio is now? Does it feel snappier with the higher compression ratio?
The shop estimated a compression ratio of 10.5:1 and yes it is noticeably snappier with cc heads on it. The machine shop had two other Clevelands they were rebuilding at the same time they were working on mine. The new owner is a big time Ford guy and talks Cleveland.

I was concerned about detonation issues with the increased compression using 92 octane fuel, but it's not an issue.

Jim

 
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