I stand corrected....But I still wouldn't attempt it....

Since I'm very good at crowing when I'm right, I feel obligated to admit when I'm wrong. In the previous post I said no one offered a manual transmission flywheel for a 403 Olds engine. A friend sent me a Summit Catalog and a company called Ram-that makes high-performance flywheels for various vehicles does offer a manual trans flywheel for 330-350-403 Olds engines. So-to the guy with the Disco-era T/A who wanted to convert his 403 / TH350 'Bird to a 4-speed-it is possible. However-the hassle and expense of chasing down a Muncie or T10 trans, a manual trans crossmember,a Bellhousing,the clutch fork and linkage, the pedals,the disc, pressure plate and throw-out bearing, the shift linkage, and cutting a hole in the floor for the shifter is still the monumental pain in the ass and the wallet that it always was. Further-most L80 403 / TH350 T/A's had 2.41:1, 2.56:1 or 2.73:1 gears, none of which will work well with a stick. You'll need to swap in some 3.23:1 or 3.42:1 gears to get the performance increase your looking for. And here's the "Catch 22" on that-if you put 3.23:1 or 3.42:1 gears, a TransGo or B&M shift kit and a 2,000-2,400 rpm converter in the TH350 model-you'd have a spectacular improvement in 0-60 and 1/4 mile acceleration, and a lot less expense and grief of doing the stick change-over!!  So my original advice is still good advice-if you "Gotta Have" a manual transmission Firebird-just buy a T/A or Formula 400 that has a stick from the factory!  On the same subject someone had asked me about putting a manual trans in a '78-88 "G" body-i.e.-Grand National, Monte Carlo, Gran Prix, Cutlass, etc. Their rare, but GM did offer stick shift models in the late '70's and early '80's. I personally know 3 people that had them. A friend had a '78 El Camino with a 350 and a 4-speed. A guy I worked with had a '79 Gran Prix with a 301 V8 and a 4-speed, and a neighbor had an '81 Monte Carlo with a Turbo V6 and a stick. Check the Hollander Interchange Manual ( the "Bible" that junkyards use to know what parts interchange on what vehicles ) and see what you can find. Also-I would think the much more plentiful '82-92 Camaro / Firebird linkage would adapt to a "G" body pretty easily, as well as '64-77 "A" body stuff. If you just "Gotta Have" a 4 or 5-speed in your "G" body you can certainly do it-depending on the combo you want to run. If your putting a T5 behind a 305 or 350 Chevy-that's probably a snap-just find a wrecked stick-shift 305 '82-92 Camaro / Firebird and pirate everything. If your putting a Rock-Crusher behind a 454 Chevy or a 455 Olds or Pontiac-you may have to do some fabrication!!  It's possible-but it may not be cheap or easy.  I also had a couple people ask me about trans-planting fuel-injection systems. Again-you can do it, but it's going to be a major pain in the ass. If you "Gotta Have" a "Tuned Port Injected" small-block Chevy in your car I suggest going to a junkyard and finding an '85-91 Corvette, Camaro or T/A that has an L98 350 or LB9 305 in it, and get the whole engine, the wiring harness, the fuel pump, everything you can. If that's not possible, then get the induction system, the distributor, and the wiring harness. A company called Painless sells complete wiring harnesses to make this conversion easier. Edelbrock and Accel offer ported baseplates and runners, and BBK offers larger throttle bodies and higher flow per hr injectors. You can make these systems feed a 450 hp engine reliably; it just takes some time and effort. Ditto for Ford guys-find a wrecked "5.0" Mustang and get the whole engine if you can; other wise get the induction system and all the wiring. Painless offers wiring kits for this swap into other Ford bodies, and Edelbrock and Trick Flow and Ford SVT offer ported manifolds, larger throttle bodies, etc that can feed up to 400+ hp engines. Mopar guys-there are zillions of Dodge Trucks and Jeep Cherokees with 318 and 360 "Magnum" engines in them in junkyards. Get the whole shebang if you can, or at least the wiring harness, fuel pump, etc.  These system swaps work great when their done right; however a simple 4bbl carb and intake will make as much or more power, be dead reliable, and cost about 1/3 of the price and about 1/10th of the grief!!  Anyhow the path of LEAST resistance is still the way to go. As Jimmy the Greek once said-"The race may not always be to the swift, or the battle to the strong, but that's the way to bet".  Mastermind