Ok I'm confused. I thought yugo underfolders  had a bulge at the front of the receiver. I just got a kit that has what appears to have a regular receiver and is only 1mm thick. Has a flip up night sight on the front sight,has the lock on the rear trunion for the spring.  Will I be able to build this kit on regular AK receiver. the reason I bought this kit was so I could build it on a DCI receiver. Can anyone tell me about this kit. Thanks for any help. Night sight on rear sight as well. Barrel is in Exellant+ condition to.

There were some of the kits that use slab sided receivers.  A 1.6mm receiver can be used but everything has to be adjusted to make it work.  Here's a thread on another fine AK forum that shows a build, may have to register, but it is just another AK site!

On that particular kit using a good quality 1mm receiver would probably be cheapest and easiest.

slabsided Yugo UF kit build