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**cmabolt** · 07-15-2014, 03:51 PM

Headers, Headers, Headers!! Well, the headman block hugger LS headers just arrived and THEY DO FIT!!!
Passenger side might need a little trimming on the frame, but very little. PLEASE ALSO NOTE these headers are 1.5" primates and 2.25" collectors.

Passengers side drop

Drivers side no clearancing needed, but my frame has been previously.

Drivers side drop no interference and for you guys running hydraulic clutch it's not even close.

Now that I know there is a pair of ls headers out there that will work, I noticed a considerable difference in quality from the Doug Thorley headers compared to the Headman. The DT's use thicker walled tube, weld on the outside of the flange and were almost twice as heavy. Also, the DT headers use the stock style steel gasket that the factory uses to connect to the lower exhaust.
Headman pipe to flange welds

DT headers pipe to flange welds

So after a bunch of headers and one set of manifolds, I decided on the Doug Thorley exhaust manifold replacement headers for gm LS trucks
I did need to clearance the frame and the flange of the drivers header a bit to get some breathing room for the headers, but they are in and will work.

Here are the headers numbers I tried and results with a 4x4 running a hydraulic clutch and lq4 motor moved forward 2 inches:

1) Headman Mid-length HED-45666
(HIT FRT SHACKLE BOLTS AND WOULD NEED DRIVERS SIDE FRAME CLEARANCED)
2) Headman Block Hugger HED-68526
(WILL FIT FINE AND NO ISSUES WITH HYD CLTCH they have smaller primaries and collector then is desired at 1.5 primaries and 2.25 collectors)
3) Doug Thorley long tube - 324Y-C (WILL NOT CLEAR CAB OR CLEAR HYD CLTCH)
4) Doug Thorley Manifold replacement headers 309-C and 309-1-C (WILL FIT WITH DRIVERS SIDE FRAME CLEARANCED FOR FLANGE)
5) HOOKER LS MANIFOLDS 8501-1HKR (DRIVERS FLANGE HIT HYD CLUTCH SLAVE)
6) SANDERSON LS10-158 headers do not fit and interfere with hydraulic clutch.
7) SANDERSON CC1LS-158 CES Headers are very similar to the headman block huggers, but 1 5/8 primaries and 2.5 collectors. They are
also a superior header design. On both these headers it is necessary for the motor mount bolts to be inserted from the rear of the engine
so they do not interfere with collector flanges.
8) HOOKER LS BLOCK HUGGER 2313HKR Will fit but are very tight to block and motor mount bolts must both be inserted from rear of engine facing forward to allow clearance for collector flanges.

I hope this helps somebody save time and money, ordering, trying, failing and eventually winning. It has been a pain in my ass and I will probably have to reinforce the frame in that area. The clearancing took about a 1/2 inch of the frame.

07-15-2014, 03:51 PM	#181
cmabolt Registered User Join Date: Nov 2007 Location: baltimore, maryland Posts: 617	Re: Project Reno - 72 cheyenne rebuild Headers, Headers, Headers!! Well, the headman block hugger LS headers just arrived and THEY DO FIT!!! Passenger side might need a little trimming on the frame, but very little. PLEASE ALSO NOTE these headers are 1.5" primates and 2.25" collectors. Passengers side drop Drivers side no clearancing needed, but my frame has been previously. Drivers side drop no interference and for you guys running hydraulic clutch it's not even close. Now that I know there is a pair of ls headers out there that will work, I noticed a considerable difference in quality from the Doug Thorley headers compared to the Headman. The DT's use thicker walled tube, weld on the outside of the flange and were almost twice as heavy. Also, the DT headers use the stock style steel gasket that the factory uses to connect to the lower exhaust. Headman pipe to flange welds DT headers pipe to flange welds So after a bunch of headers and one set of manifolds, I decided on the Doug Thorley exhaust manifold replacement headers for gm LS trucks I did need to clearance the frame and the flange of the drivers header a bit to get some breathing room for the headers, but they are in and will work. Here are the headers numbers I tried and results with a 4x4 running a hydraulic clutch and lq4 motor moved forward 2 inches: 1) Headman Mid-length HED-45666 (HIT FRT SHACKLE BOLTS AND WOULD NEED DRIVERS SIDE FRAME CLEARANCED) 2) Headman Block Hugger HED-68526 (WILL FIT FINE AND NO ISSUES WITH HYD CLTCH they have smaller primaries and collector then is desired at 1.5 primaries and 2.25 collectors) 3) Doug Thorley long tube - 324Y-C (WILL NOT CLEAR CAB OR CLEAR HYD CLTCH) 4) Doug Thorley Manifold replacement headers 309-C and 309-1-C (WILL FIT WITH DRIVERS SIDE FRAME CLEARANCED FOR FLANGE) 5) HOOKER LS MANIFOLDS 8501-1HKR (DRIVERS FLANGE HIT HYD CLUTCH SLAVE) 6) SANDERSON LS10-158 headers do not fit and interfere with hydraulic clutch. 7) SANDERSON CC1LS-158 CES Headers are very similar to the headman block huggers, but 1 5/8 primaries and 2.5 collectors. They are also a superior header design. On both these headers it is necessary for the motor mount bolts to be inserted from the rear of the engine so they do not interfere with collector flanges. 8) HOOKER LS BLOCK HUGGER 2313HKR Will fit but are very tight to block and motor mount bolts must both be inserted from rear of engine facing forward to allow clearance for collector flanges. I hope this helps somebody save time and money, ordering, trying, failing and eventually winning. It has been a pain in my ass and I will probably have to reinforce the frame in that area. The clearancing took about a 1/2 inch of the frame. __________________ Project Reno Build http://67-72chevytrucks.com/vboard/s...d.php?t=392636 Easier to beg forgiveness than ask permission! Last edited by cmabolt; 07-08-2015 at 08:12 AM.