header questions
Thread Starter
Instructor
Joined: Jan 2011
Posts: 111
Likes: 0
header questions
Rebuilding the original small block and cylinder heads in my 73, just a bump up on cam, double roller chain & gears, flat top pistons, bored 20 over, new springs, valves, hardened valve seats. Builder expecting to produce 300-325 hp, like the look of shorty headers, like mcjacks $$$$, sanderson, just not sure of long tube, short tube, size, 1 7/8, bigger, smaller?, stainless, coated? any suggestions, looked back through some old post, too many options it seems
Melting Slicks
Joined: Mar 2001
Posts: 2,175
Likes: 56
From: Clarence N.Y.
silververt I know what you mean,soooo many choices out there.
Iam looking to put headers on my 79 L82. I will go ceramic coated for sure. Still haven't made up my mind as to shorties or long tubes.
Iam looking for a header that is easy to install and that doesn't
require any mods or starter clearance issues and fits the stock
motor mounts.
I look forward to the suggestions the forum members have.
Iam looking to put headers on my 79 L82. I will go ceramic coated for sure. Still haven't made up my mind as to shorties or long tubes.
Iam looking for a header that is easy to install and that doesn't
require any mods or starter clearance issues and fits the stock
motor mounts.
I look forward to the suggestions the forum members have.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
I have always run long tubes on mine. Started out the Hooker 1 5/8 on my LT1. These fit great with no clearance issues and fit was fine. I stepped up to 1 3/4 when I went to a 500+ HP 383. The fit was Ok but some of the clearances were a little tighter. Fit no problem but it was tighter. I now run 1 7/8 custom built headers on my LS3 motor. Obviously the fit is tight but since they are custom they fit OK. Not much room left. For a stock to mild build 1 5/8 are more than adequate.
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
I can strongly recommend ceramic coated. It is very effective at reducing under hood temps with my long tube headers. Done right it will cost, like Jet Hot, not rattle can, but worth it for reducing heat under the hood and in the cabin.
As far as primary size, bigger tubes is less back pressure.
More important might be the collector length, and back pressure producing items farther down stream, like mufflers.
As far as primary size, bigger tubes is less back pressure.
More important might be the collector length, and back pressure producing items farther down stream, like mufflers.
Le Mans Master
Joined: Oct 2007
Posts: 7,453
Likes: 976
From: RI, Now Franklin/Nashville TN
I have McJacks currently on my just built 355 L-82 AFR 180 roller cam motor and I am thinking of LTH BUT ONLY if they fit with no modifications, allow room to work in the engine bay, AND the collector (no part of the collector) does NOT sit lower than the oil pan. Any suggestions?
Melting Slicks
Joined: May 2012
Posts: 2,192
Likes: 343
From: Allenton Wisconsin
Ceramic coating is a must for our corvettes to help keep the under hood temps down. On a mild 350 build 1&5/8 headers will be good. Going bigger is only needed for very high rpm or larger cid engines. Next set I'm looking at are the Hedman Elite, they have a ball socket end on the collector [no gasket to blow out]. Your question on mods; alternator bracket mounting at exhaust manifold for lower alt pivot is part of the x manifold. You can weld nut on bracket and make up a support bracket for reinforcement or the later c3 have a cast iron bracket that bolts to front of head [preferred]. You didn't state if you had A/C. I've been checking but so far haven't found much info for mounting headers and A/C compressor @ exhaust manifold. Help needed. Picts would be nice. T
Thread Starter
Instructor
Joined: Jan 2011
Posts: 111
Likes: 0
Ceramic coating is a must for our corvettes to help keep the under hood temps down. On a mild 350 build 1&5/8 headers will be good. Going bigger is only needed for very high rpm or larger cid engines. Next set I'm looking at are the Hedman Elite, they have a ball socket end on the collector [no gasket to blow out]. Your question on mods; alternator bracket mounting at exhaust manifold for lower alt pivot is part of the x manifold. You can weld nut on bracket and make up a support bracket for reinforcement or the later c3 have a cast iron bracket that bolts to front of head [preferred]. You didn't state if you had A/C. I've been checking but so far haven't found much info for mounting headers and A/C compressor @ exhaust manifold. Help needed. Picts would be nice. T
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Drifting
Joined: Feb 2005
Posts: 1,879
Likes: 38
From: Los Gatos CA
I installed Hedman ceramic coated long tube headers on my 68 L36. Piece of cake. No fitment issues; no issues at all. Only problem is the muffler shop by my house installed Flows... Gimmie Walkers or cheapo muffler shop turbos anyday.
Racer
Joined: Jul 2008
Posts: 258
Likes: 1
From: Gippsland, VIC Australia
you could run an header size/length calculator & compare different headers on the market to get the closest match.
http://www.wallaceracing.com/header_length.php
agree on the ceramic coating
http://www.wallaceracing.com/header_length.php
agree on the ceramic coating
Race Director
Joined: Dec 1999
Posts: 11,096
Likes: 990
From: Sierra Foothills CA
Ceramic coating is a must for our corvettes to help keep the under hood temps down. On a mild 350 build 1&5/8 headers will be good. Going bigger is only needed for very high rpm or larger cid engines. Next set I'm looking at are the Hedman Elite, they have a ball socket end on the collector [no gasket to blow out]. Your question on mods; alternator bracket mounting at exhaust manifold for lower alt pivot is part of the x manifold. You can weld nut on bracket and make up a support bracket for reinforcement or the later c3 have a cast iron bracket that bolts to front of head [preferred]. You didn't state if you had A/C. I've been checking but so far haven't found much info for mounting headers and A/C compressor @ exhaust manifold. Help needed. Picts would be nice. T
1 5/8" is plenty good for you- unless you plan to stroke it to 383 and make big power in the future. Ceramic coating is well worth the $. I'd stay away from the shorty headers. They lose quite a bit of power compared to LTs. Enjoy your new engine. 
Le Mans Master
Joined: Aug 2008
Posts: 5,578
Likes: 61
From: Austin TX
Rebuilding the original small block and cylinder heads in my 73, just a bump up on cam, double roller chain & gears, flat top pistons, bored 20 over, new springs, valves, hardened valve seats. Builder expecting to produce 300-325 hp, like the look of shorty headers, like mcjacks $$$$, sanderson, just not sure of long tube, short tube, size, 1 7/8, bigger, smaller?, stainless, coated? any suggestions, looked back through some old post, too many options it seems
Stainless are the best. If you decide to go cheap with plain metal headers, make sure you at least coat them to help reduce rust.
1 5/8" will be fine, in your case.
Safety Car
Joined: Jan 2009
Posts: 3,736
Likes: 56
From: anchorage ak
Shorty headers are a power killer. I posted dyno proof in another thread, can't find the video. Basically, they're hardly better than iron manifolds.
Stainless are the best. If you decide to go cheap with plain metal headers, make sure you at least coat them to help reduce rust.
1 5/8" will be fine, in your case.
DO MA NEU!