Hi guys have some problems with my car.

before i start ill give you a little run down on what i did to the car. i am not too technical so ill explain to the best of my ability. (dont hold it against me :P)

I bored the block out to fit in bigger pistons, they are out of a mazda, they are flat top also.

When putting back together we made sure that we could turn the bottom pulley so the pistons were going up and down in the bore. all seemed ok.

put the car together and tried to start, would turn over but doesnt seem to have enough power. We checked the distributor to make sure it had spark and was firing at the right time.

I got a tow from a mate this morning to try and start, had the car in second gear and all that happened was the back wheels locked up. Didnt even kick over.

Took it back home and spun the bottom pulley with a shifter and it seems to be turning ok (its pretty tight) but it is turning(so it doesnt seem to be hitting the head).

BTW this is in a Datsun 1200 ute.

Any suggestions would be very much appreciated?

Thanks in advance
Milan