Can`t engage gears?

I have just put in a 2.5 petrol engine into my 110, old engine was a 2.5td 19j . Everything went well. Engine running okay . Whilst engine out, checked clutch fork, thrust bearing, plate and cover. All okay.
I used the clutch and plate from diesel engine after asking questions on forums and being told that they could be used and have been used in other diesel to petrol engine swaps.
On starting engine, depressed clutch which you can hear operating, but cannot get box into any gears. Why?

Checked slave cylinder, re-bled system over and over but still no gear change.

If some one can help i would be most greatful. time is of the essance as i need it back on road asap.

ta

Sounds odd...but make sure your diff lock isn't in neutral to start with..

Why didnt you droip a new clutch in??

everyone was saying that the plate an cover would fit, there was plenty of miles left on clutch plate.
Diff lock is in right position.

clutch will fit but did you tighten it up evenly as cover can warp ,clutch plate wrong way round,gearboxes for petrol or diesel are the same,push rod not fitted correctly