253 motor M21 gearbox

[HK1837]

Well I got ripped off, BIG TIME ha ha. I bought my M21 conversion for $1100:shifty:
I may have been by Road Tested spares in Campbelltown.

Well anyway what's done is done. So I spoke to aussie 4 speed and he said he would put a XU1 M21 3rd gear in and strengthen it to take 200kw for $1500 or 120kw for $900.

He said that the XU1 3rd is better and will work perfect with the 253 and a 3.36 diff.

Also for anyone that is interested he has a feature in Street Machine in the May issue.

XU-1 M20 3rd gear is the same as a normal M20. The only difference between an XU-1 M20 and a normal M20 is input shaft and cluster.
What he is doing is taking an M20 box, putting an M21 input shaft in and an XU-1 cluster.
Where you are gaining from the dude you are talking to is the strengthening of the box. Makes it capable of handling a V8 rather than being a hand grenade.
1st gear and 2nd gear ratios will still be identical to V8 M21 though, and will be a pain to take off in a big heavy car like a HQ-HZ van. The only difference is you will have a 1.25:1 3rd gear instead of 1.38:1.