Here's my problem. I am going to rebuild my 87 TBI blazer because it smokes really bad. I suspect the heads are the problem but the block seems to be in good condition. No hears is were it gets confusing. I have an 86 3/4 ton 350 carb chevy w/ 57,000 original miles but it burns 1 quart a week! suspect rings. The valves are in good condition. I want to put the block from the 86 3/4 ton into my blazer and put the "good" 87 block into my 3/4 ton. This way I only have to rebuild 1 motor. The engine in the 3/4 ton would be good. Is there an advantage/ disadvantage to keeping the 87 block with the 87 blazer? Would you recommend I do this or should I just rebuild both engines? The 3/4 ton is mainly a work horse so it doesn't matter if the engine isn't perfect. What do you think?