My GTA is getting a little tired. Id love to go 383, but whats involved? I believe id have to put a 400 crank in my L98 block, is this right? Does my motor have 5.7" rods right now? Also, what about the injectors, and throttle body? will an AFPR work with a bigger TB? One more thing, will the performance gains be worth the work and money? how much of a difference will it make? Please guys, answer all the questions you can. THX 
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1989 GTA, L98/auto, t-tops, Black w/ grey int.
Ran a 14.85 @ 93.4 mph w/ 305 exhaust (2 little crossflow mufflers), descreened MAF, TB coolant bypass, and casting wall ground down behind throttle plates.

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1989 GTA, L98/auto, t-tops, Black w/ grey int.
Ran a 14.85 @ 93.4 mph w/ 305 exhaust (2 little crossflow mufflers), descreened MAF, TB coolant bypass, and casting wall ground down behind throttle plates.
Junior Member
From what I've heard a 383 can make at least 400 hp. I'll say it's worth it, if you do it right. I'm planning on having Lingenfelter Performance build me a 383 stroker and turn my docile '87 T/A into a Mustang killer. My advice is to have someone who knows what they are doing and MUCHO DENERO!! (lots of money)
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It's all fun and games 'till someone looses an eye....then it's fun you can't see!!
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1987 Pontiac Trans Am
-305 cid motor
-700-R4 Transmission
-K&N Air Filter
-Flowmaster 40 series
Muffler
-Yokohama Tires
-GTA Rims
-3" Exhaust Tips
-180 degree Thermostat
-2.73 Posi Rear End
-JVC Head Unit w/ Kicker subs!
-And a COOL LOOKING Flowmaster sticker on the dash!
WOO-HOO!!
*Long live the F-Body!*
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It's all fun and games 'till someone looses an eye....then it's fun you can't see!!
-------------------------
1987 Pontiac Trans Am
-305 cid motor
-700-R4 Transmission
-K&N Air Filter
-Flowmaster 40 series
Muffler
-Yokohama Tires
-GTA Rims
-3" Exhaust Tips
-180 degree Thermostat
-2.73 Posi Rear End
-JVC Head Unit w/ Kicker subs!
-And a COOL LOOKING Flowmaster sticker on the dash!
WOO-HOO!!
*Long live the F-Body!*
Supreme Member
To convert your 350 to a 383, you're correct, you need a 400 crank. You can keep the 5.7" rods but you should look at getting special stroker pistons. Another thing you need is an external damper and a 400 flywheel (not sure on the flywheel). Check the archives, there are tons of posts. I would recommend a stroker kit. Scoggin' Dickey has a great kit and Powerhouse has an inexpensive, but good kit. I don't know about the AFPR, but it should work.