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Discussion Starter #1
I'm at a point with my combo where it seems like I'm having trouble keeping the heads sealed under higher boost (20+ PSI). I'm currently running unported Victor JR heads with good valves and run FelPro 1137SD5 head gaskets on a 4.125 bore SBF 347.

After each pass at the track, my top radiator hose is hard as a rock and I have to use the pressure vent on my radiator cap to relieve the pressure. The car doesn't run hot and doesn't appear to be burning water out the tail pipes?

My question: Is it worth going to a thicker deck, better flowing head like an AFR 220 CNC or TFS High Port 225 CNC heads for the 3/4" deck? Obviously, I'd realize a serious horsepower increase with big boost as a bonus.

Or, should I just O-ring my block during the next rebuild and keep running the heads I have...turn the boost up to maybe 30 + psi?

Ultimately, I'd just like to be able to run 30+ psi boost and not have to worry about the heads lifting every pass.
 

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Top Fuel Hoops, Clark copper gaskets, 1/2" studs and insert washers in heads. This is still the best setup even if you upgrade heads. I personally would not try to run above 25psi on a MLS gasket on a SBF. That's a pretty broad statement and timing advance plays a huge role in what it will or will not tolerate. There are better heads to consider as well. Brodix has a new Head Hunter 15* SBF head that is a updated version of the Edelbrock Victor head. Flows 413cfm @.800". I'm building a guy a Drag Week engine using these and they are really nice for the money.
 

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the hip casting seal up better, I had several customers running almost 30 psi with similar heads no lifting and those cars made serious steam. Don't overlook tuneup issues. stil HIP treated casting seal up a lot better.
 

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Discussion Starter #5
Top Fuel Hoops, Clark copper gaskets, 1/2" studs and insert washers in heads. This is still the best setup even if you upgrade heads. I personally would not try to run above 25psi on a MLS gasket on a SBF. That's a pretty broad statement and timing advance plays a huge role in what it will or will not tolerate. There are better heads to consider as well. Brodix has a new Head Hunter 15* SBF head that is a updated version of the Edelbrock Victor head. Flows 413cfm @.800". I'm building a guy a Drag Week engine using these and they are really nice for the money.
I researched KTM and the Clark gaskets. I have 1/2" ARP studs currently. What are the insert washers??

The heads you recommend are WAY out of my league. I'm more in the market for a 340ish int/250ish exh cfm head. This will be all I'll ever need for my goals. I'm mostly a street car that wants to run high 7s at the track a handful of times a year.

I think my Vic JR heads are a Gen 1 head, which I've heard may be prone to cracking under higher boost? It sounds like I would be better off buying a set of High Ports and sending them to KTM for O-ringing...Hell, with the better head, intake and switch to solid roller with about a 1000 more rpm, the car will probably drop right into the 7s with the same 20 psi boost!
 

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Discussion Starter #6
the hip casting seal up better, I had several customers running almost 30 psi with similar heads no lifting and those cars made serious steam. Don't overlook tuneup issues. stil HIP treated casting seal up a lot better.
HIP casting...sounds expensive? I'll check into it though. Cheaper than new heads I'm sure. I just don't know if my unported Gen 1 Vic JR heads are worth putting a bunch of effort into them??
 

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Discussion Starter #7
Vick Jr. will go 7's with a MLS HG.. IMO the felpro gaskets are not as good as Cometic.
The thing I didn't like about the Vic JR heads is that they tell you to put a dab of RTV between the coolant port and the oil port at the back corner of the head. I did it on my first build and I had coolant issues. This past time I did not.

I think I'll be going the O-ring copper head gasket route this time. I'm tired of messing around with this thing. I just hope the copper gaskets seal up the coolant passages good enough for a street car.
 

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Porting the heads always results in better hp.
Check the cam cam specs and port your intake manifold. Treat the entire intake system from TB to down pipe as a restriction .

1/2 studs , coppers and receivers/ orings. I’ve had the best luck with 100ft/lbs top and bottom studs on head torque. If you past 115# on the studs weird things start to happen. Make sure the decks are square, this maybe an issue with the leak and there is oil leaks at the corner of the intake and head.
Take your time , it’s about quality assembly .
 

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HIP casting...sounds expensive? I'll check into it though. Cheaper than new heads I'm sure. I just don't know if my unported Gen 1 Vic JR heads are worth putting a bunch of effort into them??
it's a process done before machining post casting, edelbrock and brodix both offer treated heads.
 

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I researched KTM and the Clark gaskets. I have 1/2" ARP studs currently. What are the insert washers??

The heads you recommend are WAY out of my league. I'm more in the market for a 340ish int/250ish exh cfm head. This will be all I'll ever need for my goals. I'm mostly a street car that wants to run high 7s at the track a handful of times a year.

I think my Vic JR heads are a Gen 1 head, which I've heard may be prone to cracking under higher boost? It sounds like I would be better off buying a set of High Ports and sending them to KTM for O-ringing...Hell, with the better head, intake and switch to solid roller with about a 1000 more rpm, the car will probably drop right into the 7s with the same 20 psi boost!
tbe afr 225 and the 225 cnc high ports would be perfect for those goals, if you have a 330ish inch engii. i have all the specs of a similar effort i built 10 yrs ago, went 4.80s and 8.1x at 3300 lbs in a fox with a s480 with 22psi boost, very reliable
 

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Discussion Starter #13
tbe afr 225 and the 225 cnc high ports would be perfect for those goals, if you have a 330ish inch engii. i have all the specs of a similar effort i built 10 yrs ago, went 4.80s and 8.1x at 3300 lbs in a fox with a s480 with 22psi boost, very reliable
I'm currently running 347 big bore with 3.25 stroke with the unported Victor JR heads which I doubt flow anywhere near the AFR or highport heads.

I've been 5.50s & 8.50s at 3400 lb with current combo and 20 psi. I'd love to turn the boost up to 30 psi to get into the high 7s, but I don't think my head lifting issue is going to allow that.
 

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Discussion Starter #14
Your other option is to raise the rpm range of the motor.
20psi @ 6500rpm
20psi @ 7500rpm. <
Yes. I am currently running a high rev HR lifter (Morel) and cam shifting at about 7000 k. I am looking hard at a solid roller and shifting closer to 7800, but I doubt my heads and intake can handle the rpm air flow wise.
 

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Discussion Starter #15
The best fix is moving away from the in-line head.
I'd like to but I have a TON of money wrapped up in my in line Diamond pistons. I'd hate to buy them again. I'm sure an AFR 220 CNC or a TFS High Port 225 would do the trick. I'd have to redo my turbo kit for the high ports though.

If I go the TFS route, I will probably sell my twin kit and build a custom big single turbo kit...maybe run a BW 400 series 91 mm or something to get me where I want to be?
 
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