Hey guys, I'm planning for a future Big Block and Manual Transmission swap for my 70' Skylark 350 AT. In addition, I'll be upgrading from factory 2.56/2.76 to 3.23 gears. With that being said, I have a $3000 budget (for transmission and big block) and I plan on slowly buying the parts to do the conversion. Which brings me to my question: Should I go the cheaper and easier route with a M20/M21 or save up for a 5 speed/6speed Tremec? I'm not too concerned about gas money, since I dont travel much, and there are many trains and buses in NYC. My main concern is how the transmission will hold up to 450-500 hp/tq. I've read about M20/M21's holding up to 500hp/tq but I'm still on the fence to how legit that is. Should I save my money for the 5/6speed Tremec? Is it worth the extra cash? Or should I just get the M20/M21 and call it a day? Thank you!
Hi, If your looking at a Muncie, check out Autogear, they make a modern version, just stronger and new parts, vs old worn out 30-40 year old parts, I went through 2 before I got a M22W basically a M20 with gears cut at a stronger heilx like the old rockcrushers. I have no complaints, and have had it since 2011. Overdrive trans would be nice all depends on if you do a lot of highway driving, and you rearend gear ratio. Autogear has a overdrive version, basically a muncie turned into a 3 speed with a .7 overdrive, best of all will fit without having to mess with your floors. Regards,
You can easily have $3k in all of the parts to do the 4-spd swap correctly. It might be more or less,depending on condition of parts?and if the trans is rebuilt or not.
If you have 3k for both an Engine and a trans and you WANT a stick car and will do MOST of the work my opinion is to put 1,000-2,000 for a Muncie m20. A good one, plus all the linkage and pedals, bellhousing . Put the most money in your trans and Hope you can find a good a score with 1000 or less on an Engine. Even if you have 500 bucks left over from the trans buy a core big block and wait n save money to do it right. Shop smart and haggle if your on a budget. Don't forget the money to drill your BBB for manual transmission conversion. Don't also forget the very expensive t56 to bop adapter if you want to go that route.
