383 Stroker question
Thread Starter
Joined: Oct 2007
Posts: 1,375
Likes: 6
From: Wyoming
Car: 1995 Formula
Engine: LT1 350
Transmission: Built 4L60e
Axle/Gears: 10 bolt, Eaton posi, 3.73's
383 Stroker question
Question for anyone who knows the answer:
I want to stroke the 350 in my tpi down to a 383 and keep the tpi setup or go with a Holley Stealth Ram intake setup.
I am running vortec heads with stock valve sizes and that are machined for higher lift with the CC 986-16 springs. I am not sure how much lift the new heads will handle. From the articles, it seems that they will only handle up to a .55 lift. Maybe they can handle more, like up to a .6 lift? Does anyone know?
If I go up to 383 displacement, can I stick with the same camshaft I would use with the 350 displacement, or do I need to look at a whole new set of camshaft options?
For the 350, I want to get the Comp Cams 08-305-8 (276hr14) camshaft.
Thanks!
I want to stroke the 350 in my tpi down to a 383 and keep the tpi setup or go with a Holley Stealth Ram intake setup.
I am running vortec heads with stock valve sizes and that are machined for higher lift with the CC 986-16 springs. I am not sure how much lift the new heads will handle. From the articles, it seems that they will only handle up to a .55 lift. Maybe they can handle more, like up to a .6 lift? Does anyone know?
If I go up to 383 displacement, can I stick with the same camshaft I would use with the 350 displacement, or do I need to look at a whole new set of camshaft options?
For the 350, I want to get the Comp Cams 08-305-8 (276hr14) camshaft.
Thanks!
Last edited by New2Chevy; Mar 9, 2008 at 12:22 PM.
Joined: Sep 2003
Posts: 25,895
Likes: 429
From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Re: 383 Stroker question
you generally can step up a cam size when going with larger inch strokers but you dont have to. CC305 isnt a bad choice for that motor. You could run the XE version on a 112 lsa, thats a nice mild street performance cam for the 383. OR you could stepup to the CC306 a good cam for a 383. I'll be running something similar to that cam for my 383 HSR.
If you keep TPI, then stick with a good 350 cam like the cc305 you have in mind. If HSR you will be able to rev higher and make more power at higher rpms, so you can run a bigger cam
If you keep TPI, then stick with a good 350 cam like the cc305 you have in mind. If HSR you will be able to rev higher and make more power at higher rpms, so you can run a bigger cam
Thread Starter
Joined: Oct 2007
Posts: 1,375
Likes: 6
From: Wyoming
Car: 1995 Formula
Engine: LT1 350
Transmission: Built 4L60e
Axle/Gears: 10 bolt, Eaton posi, 3.73's
Re: 383 Stroker question
OK, so the CC306 cam would still work even for the 383 with the Vortec heads?
I wonder how it would sound idling?
I want it to sound bad ***.
I wonder how it would sound idling?
I want it to sound bad ***.
Last edited by New2Chevy; Mar 9, 2008 at 12:24 PM.
Joined: Sep 2003
Posts: 25,895
Likes: 429
From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Re: 383 Stroker question
cc306 at idle is pretty intimidating. It has 74.5 degrees of overlap, it will make a good sounding idle and really make some power on a 383. It will need a fully ported aftermarket big tube TPI setup to work best, but should love HSR/minirams
It will work ok on vortec heads but you will need to have the heads machined for screw in studs if they arent already, and you will need them machined to handle the big .540 lift of the cc306. SDPC sells modded vortecs that are good to .550 lift
It will work ok on vortec heads but you will need to have the heads machined for screw in studs if they arent already, and you will need them machined to handle the big .540 lift of the cc306. SDPC sells modded vortecs that are good to .550 lift
Thread Starter
Joined: Oct 2007
Posts: 1,375
Likes: 6
From: Wyoming
Car: 1995 Formula
Engine: LT1 350
Transmission: Built 4L60e
Axle/Gears: 10 bolt, Eaton posi, 3.73's
Re: 383 Stroker question
Thanks man!
My Vortecs are all hooked up with all the needed mods. I got the screw in studs, CC springs, and valve job. They're ready to go!! I just am not sure if they will handle the .540 exhaust lift plus the extra lift of 1.6 rockers.
So, do you think it is worth it to stroke the 350?
I mean, how much more power will I get, as opposed to just the stock 350 bottom end?
I am definitely going HSR.
My Vortecs are all hooked up with all the needed mods. I got the screw in studs, CC springs, and valve job. They're ready to go!! I just am not sure if they will handle the .540 exhaust lift plus the extra lift of 1.6 rockers.
So, do you think it is worth it to stroke the 350?
I mean, how much more power will I get, as opposed to just the stock 350 bottom end?
I am definitely going HSR.
Last edited by New2Chevy; Mar 9, 2008 at 04:08 PM.
Joined: Sep 2003
Posts: 25,895
Likes: 429
From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Re: 383 Stroker question
i replied to your PM but i'll post here again
you'll have to measure your retainer to guideboss clearance to see how much clearance you have.
I'd run the cc306 with 1.5's to keep lift down. There is no more flow on vortec heads above .500, so keep it around that with 1.5's.
.540 lift on the exhaust means you'll need atleast .600" of clearance between retainer and guide boss at full travel from valve seated, to valve fully opened with retainer hitting the guide boss/valve seal. Measure that clearance and subtract roughly .050-.060 for safety. that will give you max lift you can run on your heads.
Is it worth it to stroke the 350? i'd say yes because you'l gain a lot more torque. Hp gains will happen to, but not as much as torque. I'd say the cubes are worth an extra 20-25whp depending on the tune, using the same 306 cam. But its probly gonna be 30-50wtq difference in some spots along the powerband.
you'll have to measure your retainer to guideboss clearance to see how much clearance you have.
I'd run the cc306 with 1.5's to keep lift down. There is no more flow on vortec heads above .500, so keep it around that with 1.5's.
.540 lift on the exhaust means you'll need atleast .600" of clearance between retainer and guide boss at full travel from valve seated, to valve fully opened with retainer hitting the guide boss/valve seal. Measure that clearance and subtract roughly .050-.060 for safety. that will give you max lift you can run on your heads.
Is it worth it to stroke the 350? i'd say yes because you'l gain a lot more torque. Hp gains will happen to, but not as much as torque. I'd say the cubes are worth an extra 20-25whp depending on the tune, using the same 306 cam. But its probly gonna be 30-50wtq difference in some spots along the powerband.
Thread Starter
Joined: Oct 2007
Posts: 1,375
Likes: 6
From: Wyoming
Car: 1995 Formula
Engine: LT1 350
Transmission: Built 4L60e
Axle/Gears: 10 bolt, Eaton posi, 3.73's
Re: 383 Stroker question
I just hope I'm happy when I push the pedal on the tuned 383 stroker with the HSR.
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Joined: Sep 2003
Posts: 25,895
Likes: 429
From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Re: 383 Stroker question
if you keep 11 to 1 compression, with that 306 cam and HSR with decent heads, you'll be VERY happy.
Its gonna make a stock L98 feel like a honda civic
Its gonna make a stock L98 feel like a honda civic
Thread Starter
Joined: Oct 2007
Posts: 1,375
Likes: 6
From: Wyoming
Car: 1995 Formula
Engine: LT1 350
Transmission: Built 4L60e
Axle/Gears: 10 bolt, Eaton posi, 3.73's
Re: 383 Stroker question
The Vortec heads are decent enough, right?
And the guy who is building the bottem end wants to build it 10:1 CR.
----------
I don't know why I'm worried.
The dang thing is gonna haul butt.
And the guy who is building the bottem end wants to build it 10:1 CR.
----------
I don't know why I'm worried.
The dang thing is gonna haul butt.
Last edited by New2Chevy; Mar 10, 2008 at 11:14 PM. Reason: Automerged Doublepost
Joined: Sep 2003
Posts: 25,895
Likes: 429
From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Re: 383 Stroker question
oh yeah for iron heads, keep it 10 to 1 or as close as you can get. aluminum keep 10.5-11 to 1. Vortecs will get the job done but if you could get better, than get better. heads are the most important part of the motor and should be the most expensive part of the motor
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