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84 motor vs 87motor

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pressuresix

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is 84 motor the same as 87 exepted for oil retern in front (i mean crank, rods,piston):confused:
 
YES

The crank,rods, and pistons are the same.
The deck height is a little taller on an 84/85 block and the head bolts are tapped all the way to the head surface whereas an 86/87 likes about a 1/2" from being tapped all the way to the top.
 
I found that the oil pan and front timing cover are different on the cold air then on the hot air engines. The hot air pan has fewer bolts then a cold air pan. They both have their own bolt patterns. So, if you want to avoid drilling holes in your oil pan then be sure you have a hot timing cover and pan for a hot air engine. The timing covers both will fit the blocks, but they do not match up on the pans. The part where the oil pan mounts on a cold air comes to a point, on a hot air it is rounded with no point. So the gaskets are different also.

That what I have found so far. I am doing a hot air to cold air conversion now.
 
The pistons on the 84-85 engines are different. Not enough to make a huge difference, but durability could be severely diminished if high boost (over 20lbs) is in the plans.
Also note that many of the 85's had blocks with 20 bolt oil pans and covers. Even though the rest of the block casting is the same as the 84's with the rough cast lifter valley and the minimal number of reinforcing ribs under the intake.
The rod bolts and head bolts are also inferior quality. The 86-87 motors used high quality SPS brand head and rod bolts. I have a NA 87 engine here that had the same SPS bolts as well.
 
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