SLP headers, AFR heads, straight or L98 plugs?
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From: Prince George, BC, Canada
Car: 89 GTA
Engine: 5.7L Supercharged
Transmission: T-56
Axle/Gears: Moser 9" 3.70
ok had a chance to take off the headers and try them out on my new heads, I'am going to start a new thread on it.
Joined: Mar 2000
Posts: 5,703
Likes: 132
From: Orange, CA
Car: '90 Trans Am-12.45@110.71
Engine: 355 w/AFR 195's Elem. 400/430 HP/TQ
Transmission: Tremec T-56
Axle/Gears: 12 Bolt 3.73
Re: SLP headers, AFR heads, straight or L98 plugs?
Once and for all ....he was mixed up.
I straightened him out.
AFR makes two angles
(1)The L98 which will work with most headers.
(2)The AFR comp angle will not work with SLP headers.
they angle in "and" down unlike the L98 which only angles "in".
I straightened him out.
AFR makes two angles
(1)The L98 which will work with most headers.
(2)The AFR comp angle will not work with SLP headers.
they angle in "and" down unlike the L98 which only angles "in".
Thread Starter
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From: Evansville,IN,USA
Car: 89' T/A, 00' Firehawk
Engine: 406 Roller
Transmission: TH700R4 w/2800 stall
Axle/Gears: 3.23 Posi
Re: SLP headers, AFR heads, straight or L98 plugs?
Don thank you for the post. I was wanting to ask you about your headers anyway. Do you make 1 3/4 shorty headers w/o A.I.R. tubes? I like the fact that your y pipe is not bottle necked like the SLP's are. I have a set of SLP's that I was going to cut the flanges off and weld on 2.5 or 3 inch ball flange collectors like you use, then have a custom y pipe w/ the flowmaster mergy pipe into the 4in mufflex I have. Would a 2.5 y pipe be big enough or cause turbulence going into the 4 inch cat back?
I have a spohn tubular k member so that should help with room for the y pipe. I was wondering if it would be cheaper to buy a set of your headers y pipe.
I would go long tubes but the car will be lowered some, Eibach pro kit. I have had a set of hooker L/T and they hang pretty low. Thats why I am going to stick with the 1 3/4 shorties. If you have any ideas I would appreciate it.
I have a spohn tubular k member so that should help with room for the y pipe. I was wondering if it would be cheaper to buy a set of your headers y pipe.
I would go long tubes but the car will be lowered some, Eibach pro kit. I have had a set of hooker L/T and they hang pretty low. Thats why I am going to stick with the 1 3/4 shorties. If you have any ideas I would appreciate it.
Joined: Jul 1999
Posts: 10,950
Likes: 26
From: Orange, SoCal
Car: 1990 Pontiac Trans Am
Engine: 355 TPI siamesed runners
Transmission: Tremec T56
Axle/Gears: 12-Bolt 3.73
Re: SLP headers, AFR heads, straight or L98 plugs?
Yes, I was confused and mixed up. Sorry everyone. I edited my posts for future reference.
L98 angle works, regular angle does not.
L98 angle works, regular angle does not.
Joined: Mar 2000
Posts: 5,703
Likes: 132
From: Orange, CA
Car: '90 Trans Am-12.45@110.71
Engine: 355 w/AFR 195's Elem. 400/430 HP/TQ
Transmission: Tremec T-56
Axle/Gears: 12 Bolt 3.73
Re: SLP headers, AFR heads, straight or L98 plugs?
Don thank you for the post. I was wanting to ask you about your headers anyway. Do you make 1 3/4 shorty headers w/o A.I.R. tubes? I like the fact that your y pipe is not bottle necked like the SLP's are. I have a set of SLP's that I was going to cut the flanges off and weld on 2.5 or 3 inch ball flange collectors like you use, then have a custom y pipe w/ the flowmaster mergy pipe into the 4in mufflex I have. Would a 2.5 y pipe be big enough or cause turbulence going into the 4 inch cat back?
I have a spohn tubular k member so that should help with room for the y pipe. I was wondering if it would be cheaper to buy a set of your headers y pipe.
I would go long tubes but the car will be lowered some, Eibach pro kit. I have had a set of hooker L/T and they hang pretty low. Thats why I am going to stick with the 1 3/4 shorties. If you have any ideas I would appreciate it.
I have a spohn tubular k member so that should help with room for the y pipe. I was wondering if it would be cheaper to buy a set of your headers y pipe.
I would go long tubes but the car will be lowered some, Eibach pro kit. I have had a set of hooker L/T and they hang pretty low. Thats why I am going to stick with the 1 3/4 shorties. If you have any ideas I would appreciate it.
I can make the 2 1/2" y-pipe exit into a 3 1/2" but that is the biggest I can do.
These will fit L98 angle heads and straight.
Send me a PM for more info.
Member
Joined: Aug 2003
Posts: 171
Likes: 3
From: Downriver Area, Michigan
Car: 89' IROC-Z
Engine: HSR B2L 350ci w/LT4 hotcam and AFR 195's
Transmission: Transgo'd 700R w/Yank 2800
Axle/Gears: 9 Bolt, 3.45
Re: SLP headers, AFR heads, straight or L98 plugs?
3926 is normal length, it is not a shorty. Compared to a 3923 the only difference is a slightly narrower collar on the 3926, just by a few hairs and it will not make any difference at all for clearance.
So either you got an older style plug which is no longer made or this info is wrong.
Cylinder #8: If you are running the L98 angle heads, the spark plug boot will touch on the SLP 1 3/4 style headers (UN-DENTED) and it WILL melt it eventually and cause arcing. Cylinder #3 is very close but its not as bad as #8.
Even running an Accel "Shorty" equivalent to an Autolite #3924 which is P/N:0416S with the AFR recommended reach of .750@14mm, the "shorty" is not very short at all. Maybe a 1/16 of an inch shorter than a regular Autolite or NGK, which is basically nothing.
You will need to run a heat-shield sock (which will touch and burn) and pray for the best. The best option for cylinder #8 when running SLP headers w/L98 angle AFR heads is to have the pipe cut/extended/welded then re-ceramic coated.
The plug that should be used for SBC AFR 195's is the Autolite #3924 or equivalent; that is if its a N/A motor with normal compression.
If you need the little teeny tiny bit of extra clearance on the headers, the Accel 0416S, can be used. The S is for "Shorty", but its not much shorter than the regular Accel 0416.
If you are running boost or a motor with 11:1+ compression, an Autolite #3923 is what AFR recommends for their SBC heads.
I know this thread is very old but after researching plugs and trying different ones for my SLP/AFR 195 combo, this info will be helpful for future viewers.
Tip: Do not run platinum plugs with a regular SBC street motor w/typical HEI ignition. Just use regular copper style electrode plugs.
So either you got an older style plug which is no longer made or this info is wrong.
Cylinder #8: If you are running the L98 angle heads, the spark plug boot will touch on the SLP 1 3/4 style headers (UN-DENTED) and it WILL melt it eventually and cause arcing. Cylinder #3 is very close but its not as bad as #8.
Even running an Accel "Shorty" equivalent to an Autolite #3924 which is P/N:0416S with the AFR recommended reach of .750@14mm, the "shorty" is not very short at all. Maybe a 1/16 of an inch shorter than a regular Autolite or NGK, which is basically nothing.
You will need to run a heat-shield sock (which will touch and burn) and pray for the best. The best option for cylinder #8 when running SLP headers w/L98 angle AFR heads is to have the pipe cut/extended/welded then re-ceramic coated.
The plug that should be used for SBC AFR 195's is the Autolite #3924 or equivalent; that is if its a N/A motor with normal compression.
If you need the little teeny tiny bit of extra clearance on the headers, the Accel 0416S, can be used. The S is for "Shorty", but its not much shorter than the regular Accel 0416.
If you are running boost or a motor with 11:1+ compression, an Autolite #3923 is what AFR recommends for their SBC heads.
I know this thread is very old but after researching plugs and trying different ones for my SLP/AFR 195 combo, this info will be helpful for future viewers.
Tip: Do not run platinum plugs with a regular SBC street motor w/typical HEI ignition. Just use regular copper style electrode plugs.
Last edited by 89Kicker_IROC-Z; Jul 17, 2022 at 02:02 AM.
Member
Joined: Aug 2003
Posts: 171
Likes: 3
From: Downriver Area, Michigan
Car: 89' IROC-Z
Engine: HSR B2L 350ci w/LT4 hotcam and AFR 195's
Transmission: Transgo'd 700R w/Yank 2800
Axle/Gears: 9 Bolt, 3.45
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