383 vs ls3
Thread Starter
Cruising
Joined: Mar 2015
Posts: 10
Likes: 0
383 vs ls3
My 1979 l48 350 engine is pretty nice and feels strong, but not enough.
Engine is attached to a manual tranny.
I'm not really aware of what mods were made by the previous owner, except the headers that can be easily spotted.
Now I'm looking for adding more power to the area of 400-450hp.
Option 1 is getting a ls3 pullout with a modern t56 tranny, lots of modifications.
Option 2 is getting a new crate engine from chevy / blueprint /etc.
Option 3 is building a stroker of the original engine.
As I see it option 2 is the easiest, I have thoughts of rebuilding the engine by myself with some help from my mechanic.
Original block says 3970010 on the block, not sure if its 2 or 4 bolt, I will try to find out when doing the next oil change.
Question is - how complex is it to go the way of rebuilding it myself, and can I get to the goal of the 450hp area.
Any input is welcome.
Engine is attached to a manual tranny.
I'm not really aware of what mods were made by the previous owner, except the headers that can be easily spotted.
Now I'm looking for adding more power to the area of 400-450hp.
Option 1 is getting a ls3 pullout with a modern t56 tranny, lots of modifications.
Option 2 is getting a new crate engine from chevy / blueprint /etc.
Option 3 is building a stroker of the original engine.
As I see it option 2 is the easiest, I have thoughts of rebuilding the engine by myself with some help from my mechanic.
Original block says 3970010 on the block, not sure if its 2 or 4 bolt, I will try to find out when doing the next oil change.
Question is - how complex is it to go the way of rebuilding it myself, and can I get to the goal of the 450hp area.
Any input is welcome.
Racer
Joined: Jul 2013
Posts: 307
Likes: 19
From: Kirkland WA
Now I'm looking for adding more power to the area of 400-450hp.
Option 1 is getting a ls3 pullout with a modern t56 tranny, lots of modifications.
Option 2 is getting a new crate engine from chevy / blueprint /etc.
Option 3 is building a stroker of the original engine.
As I see it option 2 is the easiest, I have thoughts of rebuilding the engine by myself with some help from my mechanic.
Original block says 3970010 on the block, not sure if its 2 or 4 bolt, I will try to find out when doing the next oil change.
Under 450 hp, a 2-bolt main with a good quality cast crank like Scat will work just fine IMHO.
Also, the LGT 700 5 speed from Silver Sport Transmissions was an easy fit and very strong. Personally, I do not need another taller overdrive gear, and that's the main difference with a T56.
Intermediate
Joined: Jul 2011
Posts: 48
Likes: 0
I have same question
Tagged to follow along I have the same questions
Option 1 is getting a ls3 pullout with a modern t56 tranny, lots of modifications.
Option 2 is getting a new crate engine from chevy / blueprint /etc.
Option 3 is building a stroker of the original engine.
Option 1 is getting a ls3 pullout with a modern t56 tranny, lots of modifications.
Option 2 is getting a new crate engine from chevy / blueprint /etc.
Option 3 is building a stroker of the original engine.
Racer
Joined: Jul 2013
Posts: 307
Likes: 19
From: Kirkland WA
When I went through my build planning process I went with what I know works. Very good power, easy install, and fairly priced.
Now I'd like to hear from someone that's done an LS3. If for no other reason, I wish I didn't have the Gen 1 tuning responsibilities.
Now I'd like to hear from someone that's done an LS3. If for no other reason, I wish I didn't have the Gen 1 tuning responsibilities.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
I went from a well built 350 to a 383, then a fuel injected roller crammed 383. Now I have an LS3 in it. I have driven the LS3 much but I can tell you it will produce as much if not more power with less issue. It was a lot more expensive to go this route though. It all depends if you are old school or like modern technology.
Melting Slicks
Joined: Jun 2011
Posts: 3,116
Likes: 598
My 1979 l48 350 engine is pretty nice and feels strong, but not enough.
Engine is attached to a manual tranny.
I'm not really aware of what mods were made by the previous owner, except the headers that can be easily spotted.
Now I'm looking for adding more power to the area of 400-450hp.
Option 1 is getting a ls3 pullout with a modern t56 tranny, lots of modifications.
Option 2 is getting a new crate engine from chevy / blueprint /etc.
Option 3 is building a stroker of the original engine.
As I see it option 2 is the easiest, I have thoughts of rebuilding the engine by myself with some help from my mechanic.
Original block says 3970010 on the block, not sure if its 2 or 4 bolt, I will try to find out when doing the next oil change.
Question is - how complex is it to go the way of rebuilding it myself, and can I get to the goal of the 450hp area.
Any input is welcome.
Engine is attached to a manual tranny.
I'm not really aware of what mods were made by the previous owner, except the headers that can be easily spotted.
Now I'm looking for adding more power to the area of 400-450hp.
Option 1 is getting a ls3 pullout with a modern t56 tranny, lots of modifications.
Option 2 is getting a new crate engine from chevy / blueprint /etc.
Option 3 is building a stroker of the original engine.
As I see it option 2 is the easiest, I have thoughts of rebuilding the engine by myself with some help from my mechanic.
Original block says 3970010 on the block, not sure if its 2 or 4 bolt, I will try to find out when doing the next oil change.
Question is - how complex is it to go the way of rebuilding it myself, and can I get to the goal of the 450hp area.
Any input is welcome.
78 is a ZZ383 with a T56 Magnum. Of the 2 upgrades engine vs T56, I like the T56 vs the ZZ383. If I would do it again, I would do the LS3 & T56 Magnum. After learning how to do the T56 Magnum install its much easier the second time. Looks tough, but most of the issues are the same for all manual transmission. There is not complete kit, but you can purchase everything you need without making your own parts. You still need to cut & mount items but that is still required for any 5 or 6 speed install.
Here are my T56 magnum install Notes.
https://www.corvetteforum.com/forums...-corvette.html
I cannot speak about a LS3 install but with a long winter in my area this would be a great project coming this fall. The LS3 is a no maintenance upgrade engine. Is it a simple upgrade, I think not, but then I also installed a 6530 Programable MSD in my ZZ383. I like electronic controlled anything. The problem with the LS3 & T56 for most is justifiying the cost. This is not a cheap upgrade. I would think in the 10k - 15k range.
Last edited by cagotzmann; Jul 8, 2015 at 10:25 PM.
Pro
Joined: Jun 2002
Posts: 662
Likes: 2
From: chatam nj
We had the same 3 options for a customer. They went with the lt1 from a c4. Nice mods to it with headers and dual exhaust came to 405 hp,even with minor mods you can get 350hp. Worth getting the lt1 and fuel injection IMO.
Racer
Joined: Jul 2008
Posts: 258
Likes: 1
From: Gippsland, VIC Australia
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Drifting
Joined: Nov 2000
Posts: 1,536
Likes: 10
From: Sault Ste Marie Ontario
I blew up my heavly rebuilt 355 and swaped in a 383 stroker with aluminum fast burn heads from GM, needed to purchase another intake and headers and flywheel. Very pleased with results. Lots of torque. On highway driving speed limit gets 20 mpg. I can also burn 1/4 tank in a half hour fooling around. Pleased with the purchase
Melting Slicks
Joined: Feb 2009
Posts: 2,797
Likes: 608
From: Dallas Georgia
2020 Corvette of the Year Finalist (track prepared)
C3 of Year Winner (track prepared) 2019
The LS3 swap will be much more expensive by the time all is said and done. From setting up your fuel pump, to converting or adapting your gauges...it just cost more.
That said, the LS3 and TKO in my 71 completely makes the car, in my opinion. I have a 700hp big block Chevelle and enjoy "driving" the Corvette more, although it gets less attention.
That said, the LS3 and TKO in my 71 completely makes the car, in my opinion. I have a 700hp big block Chevelle and enjoy "driving" the Corvette more, although it gets less attention.
Drifting
Joined: Sep 2010
Posts: 1,412
Likes: 50
From: Laguna Niguel California
One more thing about a crate replacement, you can get a modern block that is already equipped for a hydraulic roller cam. Also it's an opportunity to get modern technology heads. These two thing are IMHO the biggest drawbacks to keeping your original 350.