The bolt up should be straight forward. You may need to move the transmission mount but I'm not sure. One thing you will definately need is a bigger radiator. Go with a 3 core or the big sucker 4 core. The exhaust will need some routing and additions. Do you have the exhaust manifolds. You could probably find a "y" off a late '80 truck to fit nicely.
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Gerardo
1983 Custom Truck
TX Plates: "BAD BOW"
http://www.geocities.com/abetterchemist/