O.k. so the 4.3 chevy engine isnt a huge power builder, however, when mine is completed i hope itll be worth the trouble. Any ways deal is; i needed some taller center bolt valve covers for a 4.3 so the full roller rockers im putting on the engine will fit. Lo and behold almost no one sells them, some company out west will make them for 425!! Too rich for my blood, so i bought 4 valve covers for 20 bucks cut the tops off of two of them, cut the sealing ring off the other two, and welded them together, bolts go through perfectly and gaskets seal, however since the engine isnt in the truck yet i may run into problems with clearance with the brake booster, we will see, but if any one else has had this problem, or has a vortec chevy motor and wants to build some inexpensive valve covers, it works!! and best part is you can choose the height! Ill post some pictures if anyone wants to know more.. just thought id let you guys know.