My '81 Monte was an original 229 with a 2.41 befor my V8/4 speed conversion. I used a 3.11 1st gear Saginaw which was OK & spun the one wheel wonder in all 4 gears but didn't live long. The replacement was a 2.29 which was the only rear handy at the time. It was good for gas mileage with fair take off but wasn't taking the lead at the light. Now it has a 2.73 which with the 3.11 is close to a 2.52 Muncie with a 3.08. This is the same combo that'll be in my boy's '79 Monte. It's all about doing the math compairing 1st gear/rear end gear combos to see what could act like the performance combos. A deep 3.50 could ley you go under 2.73 but might make 4th feel like over drive & won't me good for most in town driving.
Now for the shifter. Hurst does list a Comp Plus shifter for our cars but some years back discontinued the complete install kit with all but a few parts also being discontinued. The GM ITM shifter is out there but hard to find & not always complete. On good thing is the 3 & 4 speed share parts other than 3 & 4 speed specific parts. The GM installed Hurst shifters (used '78-'79 & mainly in Pontiacs) are very simular to the ITM other than the shift gate guts being Hurst design. They share the rods, arms & mounting parts. There is one Comp Plus on Ebay but they seller wants almost $1K for it. He also has a restored GM installed Hurst for the same amount. Regardless, the shifter mounting bracket needs a Saginaw with a flat side tail housing to fit the transmission. The side cover should have the back up light switch boss casted in like the factory stick cars.
Search the site & you can find a thread on making a Muncie or T10 work in the stock shifter location. I keep forgetting the member's name but he did a very good job on the modification.
If you want to use stock clucth linkage most of it is repopped but some parts are claimmed to fit but are far from able to. Have to find the correct '78-'81 A-body specific bellhousing. Most likely it'll be for a 10.4"clutch/153 tooth flywheel. I do believe
gnvair has a 11" clutch/168 tooth flywheel bellhousing for sale on Ebay. The clutch fork is also specific to our cars. Then there is the firewall clutch rod boot. Currently El Camino Manufacturing owns the original GM boot molds but don't have a molder to make them or have any instock. They are currently trying to sell a 2nd gen F-body boot as a fit but doesn't. Most venders who have boots listed in stock also have them too. I'm working on finding a good alternate that'll work for the boy's car as we need one. Might be a good idea to even check out hydraulic throw out bearing which there are mount plates made for the slave cylinder mounting in our cars. The steel hump, plastic trim hump, boot & bezel are also repopped. Your original carpet might have the glued on under pad with the location for the hump precut. The hard to find part will be tring to get a '79-'81 manual shift column for the ease of keeping your original ignition lock & key if you want the original look but it won't have the wiper/turn signal switch but a little body work on the column shifter mount it'll look like a floor shift column.
There are possible used sources for the bellhousing like mechanical clutch linkage '82-'84 F-bodies with V8/4 speeds but I'm not 100%. The aftermarket TKX supose to have a stock location shifter for our cars but I never dug into that & not sure how much you really want to throw into this project. This would allow you to run a 3.42 or deeper rear gear.
You'll have to understand the best route to do this is based on budget, how original looking you want it, what you're willing to change to get the conversion done & would you might want to upgrade from a Saginaw to something stronger.
