ENGINE PREDETONATION ON 2.6L AND NEED WEBER CARB.

Have a '88 dodge ram sport 4x4 2.6L Having a problem with predetonation. In the past will not run above 50 without valves clanging like crazy and losing power. Now it starts and takes gas fine (revs up normal), but has no power when put in gear and engine will not rev up even when given full throttle. Is this a carb. problem? or timing or other issues? Replaced head with a head from a 1982 2.6L d-50 engine. The only difference is the '82 head has more metal around the valves than the '88 head and the intake bolts are reversed on the lower part of intake which I managed to use washers and nuts to hold it. Top matches fine. Rebuild the engine about 5 yrs ago (about 15K miles). Now I have a blown head gasket between the 2 inter cyclinders. Would the predetonation be the cause of this? Also, looking for a Weber carb. kit wk614.

That sounds like a major vacuum leek. Does the new 82 head have mechanical adjusters or hydraulic adjusters. As for more metal around the valves that tells me the valves are smaller. I want to say there is a difference in CC on the head and you changed your compression ratio.
Did you use new head bolts when replacing the head?
When you rebuilt the engine did you have the deck surfaced? If so then you need to run the thick head gasket. Not the stock thickness. Otherwise you changed your cam timing.

In my comparsion, I think the mfg. took the 82 head and shaved around the combustion area. I believe that is why the heads on the 88 model crack very easily. They made the areas around the water jacket too thin. Thanks for the input