I'd like to get a new (and cheap) transmission case and hopefully do some gear swapping, since my case has sustained some damage and I apparently should do a total teardown.

I have an M2Y4 (97-01 Prelude Base 5spd) transmission...which transmissions are INTERNALLY compatible (M2L5, P2A4/5, P2U5?)

Can I buy an M2L5 transmission and put my gear clusters/diff into it without any modification? Could I further take the 5th gear set from the M2L5 and put it on my M2Y4 gear clusters?

I'm sure I've seen this type of info, but I can't find it now.

 

Can anyone comment on my thoughts of putting my M2Y4 (99 Prelude Base) transmission guts into an M2L5 (93 Prelude S) transmission case? Will the gear clusters fit? Will my gears fit on those shafts? Is the case of comparable robustness? Will this suck with my current or future set up (details below!)?

I ask because there's a good M2L5 from a local wrecking yard for cheap...

I know I can take my current Quaife diff and toss it into the M2L5, but I'm not sure I like the gear ratios, at all. I think I'd like to keep my current 1-4 and use the M2L5 5th, for better economy, if possible. Though, maybe the entire M2L5 would be OK? Or, I could just swap my FD and split the difference, but 1st gear would be even shorter, which is an issue.

Particulars:
Engine is a supercharged H22(see dyno below, with slipping belt and VTEC crossover too low.) I'm hoping to make quite a bit more power with a header, ported supercharger, intercooler and more boost...goal is 300whp. and a large swath of 200-220ft-lbs

At the power level of the graph, with an open diff, 1st gear is close to worthless at WOT. 2nd gear spins after the VTEC crossover. So, both of those gears could possibly be longer, but the LSD and some better rubber might also solve it. Thoughts?

This is a street car and I don't really have any other plans for it, except some autocross for fun, and maybe a track day if I'm feeling randy.

M2Y4.................M2L5
5g H22 Base........F22A1
3.29..................3.31
1.96..................1.81
1.34..................1.23
1.03..................0.9
0.79..................0.71
4.27..................4.06

SPEEDS@7400rpm
M2Y4.................M2L5.....M2L5 w/M2Y4 FD.....M2Y4 w/M2L5 FD
37.79.................39.39.............37.47..... ........................39.71
63.47.................72.04.............68.53..... ........................66.7
92.38.................105.84...........100.68..... ......................97.07
120.07...............144.88............137.42..... .....................126.17
157.76...............183.65............174.7...... ......................165.76

Cruising RPM in 5th Gear @ 70mph
3300..................2800..............3000...... ........................3150

 

any h22/h23 will fit in any cluster has long has you have both gears from each cluster..if that makes since..