Doug Thorley headers ?
Thread Starter
Burning Brakes
Joined: Feb 2006
Posts: 1,223
Likes: 4
From: Regina Saskatchewan
Doug Thorley headers ?
Has anyone had any experience with the Doug Thorley "Tri-Y" headers?
And does anyone know if they'll fit a '79 vette? Doug Thorley catalogue says they fit up to a '77 , but Summit says they'll fit to an '81. I've got the L-48 with a slight cam - .454 lift , 700R (nice) , 2500 stall converter and 2.5" duels and I'm about to stick on some Vortecs. These headers are 'supposed to' be great from idle to 4500 rpm. I'm looking at gas mileage (who isn't - we're paying $4.07 /gal up here in Canada) and a little extra hp (of course) Anyone?
And does anyone know if they'll fit a '79 vette? Doug Thorley catalogue says they fit up to a '77 , but Summit says they'll fit to an '81. I've got the L-48 with a slight cam - .454 lift , 700R (nice) , 2500 stall converter and 2.5" duels and I'm about to stick on some Vortecs. These headers are 'supposed to' be great from idle to 4500 rpm. I'm looking at gas mileage (who isn't - we're paying $4.07 /gal up here in Canada) and a little extra hp (of course) Anyone?
Race Director
Joined: Apr 1999
Posts: 11,520
Likes: 13
From: CORVETTE 77 385 C.I. TEXAS
Tri-Y are for mild setups. From what little info. is given, your cam should be good to at least 5000+.
Headers can increase mileage.
The Dynomax Corvette SB Cerama-Coat headers fit & flow great, much better than is commonly known. I have been rec. them & many have them now.
Headers can increase mileage.
The Dynomax Corvette SB Cerama-Coat headers fit & flow great, much better than is commonly known. I have been rec. them & many have them now.
Thread Starter
Burning Brakes
Joined: Feb 2006
Posts: 1,223
Likes: 4
From: Regina Saskatchewan
thanks guys. I've really been disappointed with the torque of this engine. The car has NEVER been able to spin the tires. Not stock , not with the cam install , not with the 700R install ! The cars got 3.55 gears and with the 700R I figured I'd have all kinds of go. Nope. 
I'm not so much after hp , but after torque - the kick in the but off the line kind. I'm not so sure the 2 bolt main L-48 can handle much over 4500 rpm , so thats why I was looking at the Thorley headers.
Can the "stock" crank/pistoned L-48 rev much passed 4500 rpms?
I'm not so much after hp , but after torque - the kick in the but off the line kind. I'm not so sure the 2 bolt main L-48 can handle much over 4500 rpm , so thats why I was looking at the Thorley headers.
Can the "stock" crank/pistoned L-48 rev much passed 4500 rpms?
Racer
Joined: Feb 2006
Posts: 324
Likes: 0
From: South Elgin IL
Melting Slicks
Joined: Mar 2006
Posts: 2,465
Likes: 0
From: Orange Park Fl
thanks guys. I've really been disappointed with the torque of this engine. The car has NEVER been able to spin the tires. Not stock , not with the cam install , not with the 700R install ! The cars got 3.55 gears and with the 700R I figured I'd have all kinds of go. Nope.
I'm not so much after hp , but after torque - the kick in the but off the line kind. I'm not so sure the 2 bolt main L-48 can handle much over 4500 rpm , so thats why I was looking at the Thorley headers.
Can the "stock" crank/pistoned L-48 rev much passed 4500 rpms?
I'm not so much after hp , but after torque - the kick in the but off the line kind. I'm not so sure the 2 bolt main L-48 can handle much over 4500 rpm , so thats why I was looking at the Thorley headers.
Can the "stock" crank/pistoned L-48 rev much passed 4500 rpms?
Le Mans Master
Joined: Oct 2000
Posts: 8,897
Likes: 1,357
From: Santa Ana CA
Has anyone had any experience with the Doug Thorley "Tri-Y" headers?
And does anyone know if they'll fit a '79 vette? Doug Thorley catalogue says they fit up to a '77 , but Summit says they'll fit to an '81. I've got the L-48 with a slight cam - .454 lift , 700R (nice) , 2500 stall converter and 2.5" duels and I'm about to stick on some Vortecs. These headers are 'supposed to' be great from idle to 4500 rpm. I'm looking at gas mileage (who isn't - we're paying $4.07 /gal up here in Canada) and a little extra hp (of course) Anyone?
And does anyone know if they'll fit a '79 vette? Doug Thorley catalogue says they fit up to a '77 , but Summit says they'll fit to an '81. I've got the L-48 with a slight cam - .454 lift , 700R (nice) , 2500 stall converter and 2.5" duels and I'm about to stick on some Vortecs. These headers are 'supposed to' be great from idle to 4500 rpm. I'm looking at gas mileage (who isn't - we're paying $4.07 /gal up here in Canada) and a little extra hp (of course) Anyone?
Thread Starter
Burning Brakes
Joined: Feb 2006
Posts: 1,223
Likes: 4
From: Regina Saskatchewan
thx again ! I'll have to give Stan a call @ Stan's Headers. He might be a good alternative to Thorley. I'm kinda stuck on this tri-y idea. It seems to make sense. I don't think this car and I will ever be at the track or zippin her over 5000 rpm much. Just want to know that next time some Triburon tries to take me on , I could kick his butt 'if' I wanted to.
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Thread Starter
Burning Brakes
Joined: Feb 2006
Posts: 1,223
Likes: 4
From: Regina Saskatchewan
cam is .454 lift 272/272 advertised duration and 216/216 @0.05
I've got a local shop putting some Vortecs together , then I've got to
find a manifold , get some headers blah blah blah. Anyway I've had
the car scoped/tuned. Mechanic says the carb is tired, could use a
rebuild. I'm thinking just popping a 600 - 650 Holley on it (When I
get some more $$$ that is )
I just missed buying a ZZ4 by a day. Local guy had one for sale for
$4 G - still in crate. I phoned down to chevy dealership and they
want $7900 + taxes. (Canadian) Aughhh too much !!! I'll just keep plugging away with the bolt ons.
I've got a local shop putting some Vortecs together , then I've got to
find a manifold , get some headers blah blah blah. Anyway I've had
the car scoped/tuned. Mechanic says the carb is tired, could use a
rebuild. I'm thinking just popping a 600 - 650 Holley on it (When I
get some more $$$ that is )
I just missed buying a ZZ4 by a day. Local guy had one for sale for
$4 G - still in crate. I phoned down to chevy dealership and they
want $7900 + taxes. (Canadian) Aughhh too much !!! I'll just keep plugging away with the bolt ons.
