Progress Thread Diagnosis front end clunk (and more)

JD1964 · Apr 1, 2026

This is the driver’s side Cometic head gasket. The picture shows the side that mates with the head. It was good NA but puking coolant under boost above 5psi. I’ve been suspicious of the GT40 iron head (probably milled enough to weaken it). I think it’s been lifting meaning it’s never been a head gasket failure but always the weak head deck.

Can you find the failure point on this gasket? I think I see it

AeroCoupe · Apr 1, 2026

Looks like the end at the top failed in a couple of spots. Are you running studs or bolts and did you retire them after a heat cycle?

JD1964 · Apr 1, 2026

Me thinks this is the failure spot

JD1964 · Apr 1, 2026

Top side of the gasket at cylinder #7

Noobz347 · Apr 1, 2026

In the image, it looks like this is the failure point. It's the only portion where the rim for cylinder looks mangled...

In this part, the two cylinders look like they were swapping spit:

TOOLOW91 · Apr 1, 2026

How much boost does it make ?

The highlighted cylinder definitely shows some carbon tracing from cylinder leakage. But not the end of the world per say

What went on with cylinder 5 ? You have an even amount of copper spray everywhere but there is some big clean or transfer spots like it was clamped harder or different there. The corner as noobz mentioned doesn’t look so good either.

I will say I don’t recommend mls gaskets on a stock unprepped block. I’m sure the iron head doesn’t have a fine enough RA to seal the gasket either and the copper spray is the bandaid for that but you’re seeing the affects of it still not sealing.

In this application I can’t see how a 9333pt1 wouldn’t be more than enough. It’ll definitely seal as well.

JD1964 · Apr 1, 2026

ARP studs and re-torqued

JD1964 · Apr 1, 2026

I’m using 9333 this time along with AFR Renegade heads.

JD1964 · Apr 1, 2026

TOOLOW91 · Apr 1, 2026

JD1964 said:
I’m using 9333 this time along with AFR Renegade heads.

The thicker deck should seal much better and stay flat.

8 psi doesn’t call for a cometic head gasket at all, so I’m glad you went with the 9333pt1.

I think you’ll be in much better shape this time around.

Stock pistons ? Or do they have bigger reliefs or fly cut ? With a renegade head you will most likely run into PTV issues if not.

JD1964 · Apr 1, 2026

Stock forged pistons. I have the Renegade 1472 heads. These are the only SBF AFR heads compatible with stock pistons. Stock HO roller cam and Ford Racing full roller rockers at 1.7. These 1472’s are pedestal mount rockers which is what have.

TOOLOW91 · Apr 1, 2026

They are a 165 that’s makes sense. Usually when I hear renegade it’s usually the 220s that’s why I mentioned it.

JD1964 · Apr 1, 2026

They’re what fits all the parts I have

TOOLOW91 · Apr 1, 2026

JD1964 said:
They’re what fits all the parts I have

Absolutely, there’s a few others as well but for what you’re doing it’s a good head

JD1964 · Apr 2, 2026

I’m gonna set it up NA initially and see how it feels. Then I’ll train myself with Binary Editor and Quarterhorse which I already have all that stuff. Once I feel comfortable with that I’ll put the blower back online and re-tune. I’m running 42lb injectors with calibrated Pro M MAF and I have a data sheet with the MAF voltage values. I have a wideband to monitor AF. Walbro in tank 255 pump. Explorer intake and 65mm TB

JD1964 · Apr 2, 2026

What header gaskets do you like? I was a fan of Percy’s dead soft aluminum pn66018 but it appears they’re no longer made, at least not by Percy’s. When I ordered they sent me 66018 made by Patriot and frankly I’m not impressed by the appearance of quality out of the box.

I really really need some that arent going to burn because my x pipe closer to the engine makes replacing them more difficult.

JD1964 · Apr 2, 2026

Maybe these?

Ford SB 289 302 351 Windsor Copper Exhaust Gasket Set

OverviewThese Speedmaster exhaust gaskets are made from thick copper, and feature an embossed ridge around the exhaust port for a tight, leakproof seal. The copper gaskets help even out the flow between the head and header flange to minimize warping. Also, they'll conform to rough or irregular...

www.speedmaster79.com

JD1964 · Apr 2, 2026

Or these

https://lmr.com/item/LRS-9450C/1979-95-Mustang-50-58L-Performance-Copper-Header-Gaskets?utm_source=google&utm_medium=cpc&gad_source=1&gad_campaignid=20122150522&gbraid=0AAAAAD62FUyxdhBe26z2YsoRtWiS5iWkc&gclid=EAIaIQobChMIkr-y1vrPkwMVJEVHAR0lkwpbEAQYBSABEgKFjfD_BwE

JD1964 · Apr 2, 2026

Better yet, check out this Remflex catalog. It clearly is defining specific details of various applications giving me some faith that they understand its not a one size fits all situation.

Windsor Engines - 289, 302, 351

Finally! An exhaust gasket that really works! 100% graphite construction means Remflex gaskets can take the heat-up to 3,000º F! A built-in 50% crush allows Remflex gaskets to fill gaps in headers or exhaust manifolds up to 1/16-inch inch. No more leaks…ever! Remflex gaskets are designed to...

catalog.remflex.com

JD1964 · Apr 2, 2026

I just measured the head ports and my actual header port dimensions. The Remflex 3028’s are a perfect fit! Gonna give them a try.

Progress Thread Diagnosis front end clunk (and more)

there is enough sticking out to grab on to

lube between the nut and the face. I know my lubes

there is enough sticking out to grab on to

there is enough sticking out to grab on to

Stangnet Facilities Maint Tech... Er... Janitor

If you're the village idiot what's that make me?

there is enough sticking out to grab on to

there is enough sticking out to grab on to

there is enough sticking out to grab on to

If you're the village idiot what's that make me?

there is enough sticking out to grab on to

If you're the village idiot what's that make me?

there is enough sticking out to grab on to

If you're the village idiot what's that make me?

there is enough sticking out to grab on to

there is enough sticking out to grab on to

there is enough sticking out to grab on to

there is enough sticking out to grab on to

there is enough sticking out to grab on to

there is enough sticking out to grab on to

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