Lt1 383 or Stealth Ram 400 Swap
07-28-2017, 10:17 AM
#1
Member
Thread Starter
iTrader: (1)
Join Date: Apr 2013
Location: Ohio
Posts: 372
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1987 Trans Am
Engine: 305 TPI
Lt1 383 or Stealth Ram 400 Swap
I have an 88 GTA I am planning to do a larger engine build on after I have finished up my current project. Only reason I'm bringing this up now is I have the option to pick up a complete running LT1 with an auto trans from a 93 Trans Am and was looking for opinions on doing a complete swap.
Car is an 88 GTA roller with digital dash, was a 350 auto car, hardtop. Since I have a blank slate I was looking to build the car for some street/strip/autocross type use. I was thinking of going with a built 383 or 400 sbc topped with a stealth ram.
Most of the lt1 threads seem to be older on here so I was looking for opinions on the better route from those who have done the swaps. Is the wiring and swap for the lt1 platform worth it over the traditional sbc with a stealthram intake? I would likely build the lt1 block as a 383.
Car is an 88 GTA roller with digital dash, was a 350 auto car, hardtop. Since I have a blank slate I was looking to build the car for some street/strip/autocross type use. I was thinking of going with a built 383 or 400 sbc topped with a stealth ram.
Most of the lt1 threads seem to be older on here so I was looking for opinions on the better route from those who have done the swaps. Is the wiring and swap for the lt1 platform worth it over the traditional sbc with a stealthram intake? I would likely build the lt1 block as a 383.
07-28-2017, 12:07 PM
#2
Re: Lt1 383 or Stealth Ram 400 Swap
400 blocks seem to be hit or miss. If you did find a quality block that checks out well for bore wall thickness and such, then i would go cubes all day long and more parts are available for regular 2pc rms sbc than lt1
But the 383 lt1 is not junk. Block is stronger than a 400 imo. If you did that, i would look into the 24x ls1 pcm conversion from eficonnection to get rid of optispark. The wiring conversion is simple, basically get a ls1 motor harness and move a few things around. Easier to tune that way but costs more than 94-95 lt1 systems
Lt1 heads are great for port work from advanced induction or lloyd elliott if hes still in the game.
But the 383 lt1 is not junk. Block is stronger than a 400 imo. If you did that, i would look into the 24x ls1 pcm conversion from eficonnection to get rid of optispark. The wiring conversion is simple, basically get a ls1 motor harness and move a few things around. Easier to tune that way but costs more than 94-95 lt1 systems
Lt1 heads are great for port work from advanced induction or lloyd elliott if hes still in the game.
07-28-2017, 06:46 PM
#3
Supreme Member
iTrader: (1)
Join Date: Feb 2017
Location: Meriden, CT 06450
Posts: 4,030
Received 511 Likes
on
428 Posts
Car: 84 TA orig. 305 LG4 "H" E4ME
Engine: 334 SBC - stroked 305 M4ME Q-Jet
Transmission: upgraded 700R4 3200 stall
Axle/Gears: 10bolt 4.10 Posi w Lakewood TA Bars
Re: Lt1 383 or Stealth Ram 400 Swap
I just read this yesterday. Check out the Sept 2017 issue of Chevy High Performance - New Love for a Forgotten Engine. Keith Dorton puts a 383 crank in a Gen II LT1 and makes 529 HP @ 6200, 506 TQ @ 4800 NORMALLY ASPIRATED. Pump gas and used off-the-shelf parts to do it.
http://www.superchevy.com/how-to/eng...-engine-build/
http://www.superchevy.com/how-to/eng...-engine-build/
07-28-2017, 07:58 PM
#4
Member
Thread Starter
iTrader: (1)
Join Date: Apr 2013
Location: Ohio
Posts: 372
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1987 Trans Am
Engine: 305 TPI
Re: Lt1 383 or Stealth Ram 400 Swap
I just read this yesterday. Check out the Sept 2017 issue of Chevy High Performance - New Love for a Forgotten Engine. Keith Dorton puts a 383 crank in a Gen II LT1 and makes 529 HP @ 6200, 506 TQ @ 4800 NORMALLY ASPIRATED. Pump gas and used off-the-shelf parts to do it.
http://www.superchevy.com/how-to/eng...-engine-build/
http://www.superchevy.com/how-to/eng...-engine-build/
07-28-2017, 08:01 PM
#5
Member
Thread Starter
iTrader: (1)
Join Date: Apr 2013
Location: Ohio
Posts: 372
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1987 Trans Am
Engine: 305 TPI
Re: Lt1 383 or Stealth Ram 400 Swap
400 blocks seem to be hit or miss. If you did find a quality block that checks out well for bore wall thickness and such, then i would go cubes all day long and more parts are available for regular 2pc rms sbc than lt1
But the 383 lt1 is not junk. Block is stronger than a 400 imo. If you did that, i would look into the 24x ls1 pcm conversion from eficonnection to get rid of optispark. The wiring conversion is simple, basically get a ls1 motor harness and move a few things around. Easier to tune that way but costs more than 94-95 lt1 systems
Lt1 heads are great for port work from advanced induction or lloyd elliott if hes still in the game.
But the 383 lt1 is not junk. Block is stronger than a 400 imo. If you did that, i would look into the 24x ls1 pcm conversion from eficonnection to get rid of optispark. The wiring conversion is simple, basically get a ls1 motor harness and move a few things around. Easier to tune that way but costs more than 94-95 lt1 systems
Lt1 heads are great for port work from advanced induction or lloyd elliott if hes still in the game.
Would the extra cubes really matter between the 400 and 383 being so close? I guess the main question between the swaps is whether the lt1 efi system or Stealth Ram would be better for my purpose.
Also would the 93 ecm and wiring be reasonable to use?
07-28-2017, 08:08 PM
#6
Supreme Member
iTrader: (1)
Join Date: Feb 2017
Location: Meriden, CT 06450
Posts: 4,030
Received 511 Likes
on
428 Posts
Car: 84 TA orig. 305 LG4 "H" E4ME
Engine: 334 SBC - stroked 305 M4ME Q-Jet
Transmission: upgraded 700R4 3200 stall
Axle/Gears: 10bolt 4.10 Posi w Lakewood TA Bars
Re: Lt1 383 or Stealth Ram 400 Swap
Not sure in the condition of the 400 block internally that I have laying around but it is a 2 bolt.
2 bolt is good. That's what you want if you were to add aftermarket 4-bolt splayed main caps.
2 bolt is good. That's what you want if you were to add aftermarket 4-bolt splayed main caps.
07-28-2017, 09:12 PM
#7
Re: Lt1 383 or Stealth Ram 400 Swap
Bigger bore will allow bigger valve head and flow abit better. If you give it good port size and can port the stealth ram to match, the 400 will make more power but mainly more torque across the board
But there are alot of strong 383 lt1 cars around. How fast you wanna go.
But there are alot of strong 383 lt1 cars around. How fast you wanna go.
Trending Topics
07-29-2017, 07:25 PM
#8
Supreme Member
iTrader: (1)
Join Date: Sep 2005
Posts: 26,051
Received 1,672 Likes
on
1,269 Posts
Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: Lt1 383 or Stealth Ram 400 Swap
IMO there's not really a whole lot of power potential difference between the 2 setups.
More important factors will be things like, the overall condition of the 2 motors (everything from how many miles they have on them, on back to how far the blocks have been bored); the general quality of the build (attention to details, which can be YUUUUUUJJJJE, as anyone that has $$$$$$ tied up in a motor but just got his d*** knocked in the dirt by somebody with the same BOM can attest to); ease of the conversion for YOU; YOUR tuning/wiring/adapting abilities; and stuff like that. And of course, the transmission you want to use. I don't think the 93 4L60 not E is the king of the hill for that whole situation.
The Stealth Ram is FOR SURE hostile to the Firebird hood. Not insurmountable of course, just, another hassle.
I agree about getting rid of the OptiSpark... fantastic performance for its day, but very "fragile" in a long-term-reliability sort of outlook. Kinda put 2 things right next to each other that don't play well in the same sandbox. The LT1 will be a bit harder to maintain over the long term for other reasons as well; not least of which is, it's simply not as popular, there aren't as many in existence, but lots of the parts it needs are totally unique to it. The SR is just a cast aluminum blob that everything else that bolts to it is totally generic and so isn't as likely to face marketplace parts obsolescence.
IMO there's no real clear winner. Although, my personal preference would be the SR/400.
More important factors will be things like, the overall condition of the 2 motors (everything from how many miles they have on them, on back to how far the blocks have been bored); the general quality of the build (attention to details, which can be YUUUUUUJJJJE, as anyone that has $$$$$$ tied up in a motor but just got his d*** knocked in the dirt by somebody with the same BOM can attest to); ease of the conversion for YOU; YOUR tuning/wiring/adapting abilities; and stuff like that. And of course, the transmission you want to use. I don't think the 93 4L60 not E is the king of the hill for that whole situation.
The Stealth Ram is FOR SURE hostile to the Firebird hood. Not insurmountable of course, just, another hassle.
I agree about getting rid of the OptiSpark... fantastic performance for its day, but very "fragile" in a long-term-reliability sort of outlook. Kinda put 2 things right next to each other that don't play well in the same sandbox. The LT1 will be a bit harder to maintain over the long term for other reasons as well; not least of which is, it's simply not as popular, there aren't as many in existence, but lots of the parts it needs are totally unique to it. The SR is just a cast aluminum blob that everything else that bolts to it is totally generic and so isn't as likely to face marketplace parts obsolescence.
IMO there's no real clear winner. Although, my personal preference would be the SR/400.