ok everyone

Now we are having issues again

Going for a casual cruise, when i shifted to 4th and put foot lazily back on accelarator when the revs just red lined. Then tried 5th, same issue

Pulled off to side of road and stopped. took off slowly again went 1st, 2nd and 3rd and they are all good, but went to 4th again and same issue

Have not done any spirited driving as i have just spent so much fixing it and just want it too be reliable

Atm waiting for it to cool down, and will re try and see what happens.

I honestly don't know what could be wrong as 1st through to 3rd are fine. Its only 4th and 5th where this issue comes in

Any and all suggestions and help will be highly appricated

Cheers thomas

Manual now? Clutch slip?

Test the clutch.
Car stationary, handbrake on. Try to drive off in second. If you car doesn't move with the clutch right up and the engine doesn't stall, you will need a new clutch.

Could just be inadequate freeplay on the clutch pedal though, so the clutch doesn't fully disengage.

another way to test the clutch for those that the handbrake isnt too good, get in to 3rd gear, since it still work, slow right down till your at about 800 rpm, and put the foot down, if it slips, as madmax says, clutch will be out of adjustment. if it dosent slip, then most likely 4th and 5th gear are no longer available for you to play with. or, the mechanic that did the conversion didnt do it properly

Your description indicates that it is not selecting either 4th or 5th gear - it will not be clutch related as all other gears are OK. Possibly just the selector cables misadjusted

hahaha is all good now peoples :D

Was just the pedal needed adjusting, as mechanic failed to do this procedure.

Got up underneath the dash and adjusted :)

Automatically thought the worst as normally i never just have a simple issue

Thanks everyone for your help

Cheers thomas