L98 383 with tpi
Thread Starter
Advanced
Joined: Mar 2023
Posts: 80
Likes: 4
From: Salt Lake, Utah
L98 383 with tpi
Hello, I am currently building a 383 to put into my 86 corvette; I will be keeping the TPI. Has anyone done similar who can give me advice/problems that you have run into.
as far as tuning goes im sure it will be needed. Any known reputable tuners? I am located in utah
as far as tuning goes im sure it will be needed. Any known reputable tuners? I am located in utah
Drifting
Joined: Jun 2020
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From: Stay dangerous my friends
Not knowing much about the combination specifics and intended purpose, some general info. @Tunedport90 for tuning, he's next state over. It will run OK with the 383 and a mild cam, but much better with tuning especially if you go up a bit in injector size. I personally would recommend a TPIS-Bigmouth or similar intake lower (there are many different brands for the exact same lower) and an Arizona Speed & Marine upper, they are smoother and larger diameter, will absolutely make more torque/HP this way and it looks stock, uses stock fuel rails, an you can block off the 9th injector if the runners have that and you're doing some tuning. Many options here though, just my 2 cents for a 1986.
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Advanced
Joined: Mar 2023
Posts: 80
Likes: 4
From: Salt Lake, Utah
Its a 2 bolt main 1 piece rms hyd roller block
most likely going to bore it 30 over
using 6” rods with a dished piston and ported 041 heads shooting for between 9.6-10:1 compression.
planning on porting an extra tpi manifold i have as well as the plenum and getting bigger runners.
Disabling all egr keeping all the accessories.
cam specs:
-duration @50 220 intake 224 exhaust
-Lift .495 intake .502 exhaust
-lobe separation 110 (107 in 113 ex)
Using 1.52 roller rockers
isn’t going to be a racecar but hoping to have a good fast street-able car that looks stock
most likely going to bore it 30 over
using 6” rods with a dished piston and ported 041 heads shooting for between 9.6-10:1 compression.
planning on porting an extra tpi manifold i have as well as the plenum and getting bigger runners.
Disabling all egr keeping all the accessories.
cam specs:
-duration @50 220 intake 224 exhaust
-Lift .495 intake .502 exhaust
-lobe separation 110 (107 in 113 ex)
Using 1.52 roller rockers
isn’t going to be a racecar but hoping to have a good fast street-able car that looks stock
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Pro
Joined: Feb 2001
Posts: 509
Likes: 15
From: Calgary, Alberta, Canada
You may require a mini starter for your L98 383 motor because you will go to an externally balanced flex plate.
A suggestion to put in an adjustable fuel pressure regulator too.
Install the best intake manifold gaskets possible.
If you decide to install a new water pump, then the heater core may need repair in the distant future.
A suggestion to put in an adjustable fuel pressure regulator too.
Install the best intake manifold gaskets possible.
If you decide to install a new water pump, then the heater core may need repair in the distant future.
Last edited by Magnet; Jul 12, 2025 at 08:53 AM.
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Joined: May 2025
Posts: 614
Likes: 147
From: OK
You're going to be leaving a lot on the table power wise with the stock intake. Tuners can make it run alright but they can't make the intake flow any better. Or the heads for that matter.
Certainly better than stock though despite all that.
Certainly better than stock though despite all that.