LT1 Cylinder Head question>
Thread Starter
Race Director
Joined: Mar 1999
Posts: 12,597
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From: Bartlett Illinois
LT1 Cylinder Head question>
If you were to build a 383 or 396 LT1 motor, What cyclinder heads would you use and why?
Or if you just refreshed the bottom end of the LT1 would you use the stock castings in stock form or what would you use?
Reason I ask is a firend of mine that is computer illiterate wants to rebuild his motor, He has not decided on the Cubic inches yet, but asked me what head I would use.. I was not sure since I have an L98 and know it in and out. He was however lookign to run the ZZ409 cam in what ever he builds..
Oh, yeah this is a 93 with a 6spd, and 3.45 gears..
What would you do.
Or if you just refreshed the bottom end of the LT1 would you use the stock castings in stock form or what would you use?
Reason I ask is a firend of mine that is computer illiterate wants to rebuild his motor, He has not decided on the Cubic inches yet, but asked me what head I would use.. I was not sure since I have an L98 and know it in and out. He was however lookign to run the ZZ409 cam in what ever he builds..
Oh, yeah this is a 93 with a 6spd, and 3.45 gears..
What would you do.
Burning Brakes
Joined: Jan 2001
Posts: 1,169
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From: Manhattan
Re: LT1 Cylinder Head question> (-=Jeff=-)
Well Jeff, I don't own an LT1 either, but if I was building a 350 I'd use the stock heads, ported. If I was building a 383 on a budget I'd use the stock heads, ported. If I was going for larger displacement, 383, I'd use some 195cc heads, canfield or AFR, the 396+ I might step up to 200cc heads, in a 427 I'd use 210+cc heads.
Of course, it also depends on what cam he's gonna run (how he's gonna use the engine). In a HotCam car, I would use ported stock castings in the 350 or 383 as it won't really make power above 6200 and better flowing heads are probably not worth the extra money.
What are the specs on the ZZ409?
Of course, it also depends on what cam he's gonna run (how he's gonna use the engine). In a HotCam car, I would use ported stock castings in the 350 or 383 as it won't really make power above 6200 and better flowing heads are probably not worth the extra money.
What are the specs on the ZZ409?
Burning Brakes
Joined: Jan 2001
Posts: 1,169
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From: Manhattan
Re: LT1 Cylinder Head question> (Raistlin)
I got these specs from a google search, I couldn't find them on TPiS page.
225/225-.050 525/525 115LS
I think he could gain some hp from AFR 195 (or similar Canfield, don't hear too much about them, though) on a 350 or 383, but I don't know how much, or how much more $$$ they would be over ported stock castings.
I'd lean towards aftermarket heads on the 396.
225/225-.050 525/525 115LS
I think he could gain some hp from AFR 195 (or similar Canfield, don't hear too much about them, though) on a 350 or 383, but I don't know how much, or how much more $$$ they would be over ported stock castings.
I'd lean towards aftermarket heads on the 396.
Melting Slicks
Joined: Aug 2000
Posts: 2,388
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From: Murrysville PA
Re: LT1 Cylinder Head question> (Raistlin)
If I were to do it, I'd bolt on a set of LT4 CNC ported heads with an LT4 intake and a comp 230/236 cam like Red Rocket is running in his 396.
Thread Starter
Race Director
Joined: Mar 1999
Posts: 12,597
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From: Bartlett Illinois
Re: LT1 Cylinder Head question> (89vette)
ZZ409 Specs:
226/266 Duration @ .050
.520/.520 Lift with 1.5 rockers
112 LSA
I think if he does a stroker it would be a 383.
What are the stock intake and exhaust valves on the LT1?
are they 1.94 / 1.54?
226/266 Duration @ .050
.520/.520 Lift with 1.5 rockers
112 LSA
I think if he does a stroker it would be a 383.
What are the stock intake and exhaust valves on the LT1?
are they 1.94 / 1.54?
Burning Brakes
Joined: Jan 2001
Posts: 1,169
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From: Manhattan
Re: LT1 Cylinder Head question> (-=Jeff=-)
according to this page ( http://home.tir.com/~steveher/lt4.html ), the stock size is 1.94/1.50
I think you can use 2.00/1.55 valves in the stock seats.
I wouldn't personally spend the money on the LT4 195cc castings unless they are significantly cheaper than AFR 195cc. The LT4's flow around 240cfm stock, compared to around 210cfm for the LT1's. You can port the LT1's to around 260/270, the LT4's I've read are good for a bit over 300cfm. AFR says their 195cc heads flow 280cfm (i think).
To me it would come down to the $$$. Personally, I'd port the stock heads myself. If I had to spend over $1000, I'd buy aftermarket heads, but for the L98, aftermaket heads are cheap, like $1000, for good flowing castings.
Hopefully someone with an LT1 and experience will chime in here :D
I think you can use 2.00/1.55 valves in the stock seats.
I wouldn't personally spend the money on the LT4 195cc castings unless they are significantly cheaper than AFR 195cc. The LT4's flow around 240cfm stock, compared to around 210cfm for the LT1's. You can port the LT1's to around 260/270, the LT4's I've read are good for a bit over 300cfm. AFR says their 195cc heads flow 280cfm (i think).
To me it would come down to the $$$. Personally, I'd port the stock heads myself. If I had to spend over $1000, I'd buy aftermarket heads, but for the L98, aftermaket heads are cheap, like $1000, for good flowing castings.
Hopefully someone with an LT1 and experience will chime in here :D
Pro
Joined: Sep 2002
Posts: 500
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From: Mississauga ONT
Re: LT1 Cylinder Head question> (Raistlin)
I went with the LT4 castings. Not because they are cheaper but 310+ cfm @.550 lift is more than what the afrs can do. The shoppe i go to swears that the port configuration on an LT4 is still much better than the AFRs, and that AFRs are mainly for Extremely high HP cars that require a thicker deck height > blower/turnbo/nos applications. I would have stuck with the stock LT1 heads but the shoppe reccomended the LT4s because of higher airflow capability at 7000+rpm, and with a big cam.
AFR :U :lol:
[Modified by 388 SOLid RoLLeR, 9:28 AM 12/30/2002]
AFR :U :lol:
[Modified by 388 SOLid RoLLeR, 9:28 AM 12/30/2002]
Race Director
Joined: May 2001
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Re: LT1 Cylinder Head question> (-=Jeff=-)
Stock LT1 castings that have been CNC'd with 2.00 / 1.56 valves installed. This will give you the absolute best bang for the buck. LT4 heads may give you a little more but the cost for the gain is a very high. Same with any of the aftermarket head manufacturers. :cheers:
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