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Home » Jeep Engine & Fuel System » Block Internals » Cylinder Heads » ProMaxx Performance Products ProMaxx Performance Cylinder Head with Valvetrain

Reviews for ProMaxx Performance Products CHR640N ProMaxx Performance Cylinder Head with Valvetrain for 91-06 Jeep Wrangler YJ, TJ, TJ Unlimited, Cherokee XJ, Grand Cherokee ZJ & WJ with 4.0L

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ERNEST V.
4/27/2022
5

Running great
John M.
7/21/2021
5

Great product!
Harold C.
4/13/2021
5

I have been running this head in my 2001 XJ for a year now. I was a great replacement over the tired original that came with my Jeep. Coolant flow is better, improved horsepower, smooth drivetrain. I definitely would recommend this upgrade if you are still running your stock heads. Temps have not exceeded 217 degrees, even in the hottest days of North Carolina.
Ron V.
9/4/2020
5

Beefier head!!!
Dennis D.
1/15/2020
5

Gidday my American friends, super happy with my purchase.Thanks for the speedy delivery and to you all at Quadratic. .Ups also done great. Best regards Dennis.
Pierre C.
1/14/2020
5

A really very good deal, for this brand new cylinder head...I recommand.
Michael V.
11/19/2019
5

Casting is heavier and thicker in key areas. Restored my engine to original performance after replacing my worn out head. Great quality and fast shipping. This is a heavy duty head with stock performance, worth the extra money vs a rebuild in my opinion.
Travis P.
10/28/2017
5

2003 TJ 4.0L installed at 118,000 and I noticed a good amount in power pickup and quietness of the motor over the cracked factory head
Joseph C.
5/29/2017
5

Make sure to do the lifters and cam when you change head, new top end and old bottom is not a good mix
Michael S.
10/20/2017
4

My stock head was shot this one fit perfectly and has been working great for me the only issue I had is your stock original valve cover doesn’t fit the way it did on my oem but other than that I’d recommend it.