Leaky Header-to-Block Gasket, What's the Best Fix? Chevy 250 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

71ChevySS(straight6) · 02-28-2016, 03:58 PM

Hello again! I finally got my 250 put back in and she runs like a champ, but doesn't want to idle very bad when cold, there's a fairly loud hissing/sucking noise (vacuum leak??) and an extremely definite exhaust leak around the front exhaust port, and possibly the number 4/5 ports as well (I think that bolt hole is stripped... What do I do there?).

What's the best way to seal up those exhaust leaks? I've heard good and bad about Remflex Gaskets, and I also heard someone say JB Weld lol but what do you guys suggest?

**Grumpy old man** · 02-28-2016, 04:17 PM

Well...pull the intake and exhaust manifolds and re tap the threads if there just completely wiped out re drill and install helicoils .

JB weld to seal intake and exhaust leaks ? maybe as a last ditch effort when your stuck o the side of the road .

a little info

http://www.inliners.org/ubbthreads/u...t&Number=44551

**GruntMoanCough** · 02-28-2016, 04:27 PM

Red (high heat) Silicone works well in place of an exhaust gasket.

02-28-2016, 03:58 PM	#1
71ChevySS(straight6) Registered User Join Date: Mar 2013 Location: McPherson, KS Posts: 96	Leaky Header-to-Block Gasket, What's the Best Fix? Chevy 250 Hello again! I finally got my 250 put back in and she runs like a champ, but doesn't want to idle very bad when cold, there's a fairly loud hissing/sucking noise (vacuum leak??) and an extremely definite exhaust leak around the front exhaust port, and possibly the number 4/5 ports as well (I think that bolt hole is stripped... What do I do there?). What's the best way to seal up those exhaust leaks? I've heard good and bad about Remflex Gaskets, and I also heard someone say JB Weld lol but what do you guys suggest? __________________ '71 Custom-10 2wd longbed, 250 inline-6, NP 435 four-speed. Medium Bronze Iridescent. Farm truck deluxe. Rat rod build: 1949 Crosley Station Wagon body on 1993 Dodge D350 chassis, Cadillac 500 powerplant.

02-28-2016, 04:17 PM	#2
Grumpy old man Senior Member Join Date: Dec 2013 Location: Gods country East,Tn Posts: 8,545	Re: Leaky Header-to-Block Gasket, What's the Best Fix? Chevy 250 Well...pull the intake and exhaust manifolds and re tap the threads if there just completely wiped out re drill and install helicoils . JB weld to seal intake and exhaust leaks ? maybe as a last ditch effort when your stuck o the side of the road . a little info http://www.inliners.org/ubbthreads/u...t&Number=44551 __________________ 1967 Factory short bed - Old school '71 - 350 / 4bolt / 487 heads / Edelbrock C3BX Muncie M-22 4 speed / Hurst Comp plus Factory 12 bolt posi 3.73 / 255-70-15 Smoothed firewall / Factory cowl induction Power disc brakes / power steering / 3.5-5" drop

02-28-2016, 04:27 PM	#3
GruntMoanCough Registered User Join Date: May 2009 Location: Pemberton, BC Posts: 1,075	Re: Leaky Header-to-Block Gasket, What's the Best Fix? Chevy 250 Red (high heat) Silicone works well in place of an exhaust gasket. __________________ My goal in life is to be as good a person as my dog already thinks I am - Unknown

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