1984 2.5 to 1986 Fiero (Page 2/2) 82-T/A [At Work] APR 26, 08:41 AM quote Originally posted by cartercarbaficionado: can 2nd TA's statement of the pre 87 intakes all interchanging as I have an 84 intake with a 85 tbi and 85 Block with 86 head apparently the builder liked Legos lol as for the heads its apparently late 1986 models that come with a 87 engine that have the different head Yeah, in the 1987 model year, the Duke changed entirely. Cyl head is different, and even the block is totally different. They eliminated the hole for the distributor, and added two new holes for the crank sensor. There are also THREE larger diameter bolt holes in the front of the engine where the belt tensioner mounts. This replaced the normal 4-bolt (smaller bolts) block-off plate that had the timing hole for the crank pulley on it. The 87 engine is a better design as they went to DIS ignition, a better intake design, and a newer TBI unit. It went from like 92hp to 110hp if I remember correctly. The 88 engine also improved slightly too with an internal oil filter that gets removed from within the oil pan (meaning you don't get oil all over the block), and a new balance shaft which smooths out the motor as well. I'd imagine this would probably also reduce a little bit of power because of more rotating mass, but they rated it the same.