[THEFERMANATOR]

Other than the wiring changes and adapting the EGR valve(or tuning it out), there isn't alot to the marine intake swap. It won't really help your milage any though as the only real reason to do it is to add HP(the stock spider injection is limited to about 385-400HP max due to injector sizing). A set of small diameter 1 1/2" mid length headers WILL help your milage out a noticeable amount though as well as a cam swap. COMP has there tri-power series of hydraulic roller cams and work very well. There milage cam does give you about a 1-3MPG increase with headers, but I thought it was more bark than bite myself and would reccomend there middle series torque cam as it responds very well and is smoother. You will unfortunately have to either go with the special crane or comp beehive springs, or machine the heads to run any sort of lift cam(stock spring set-up will bind at 475 lift). Also you are limited to a single roller timing chain set(the CLOYES is the cheapest and they make them for GM performance) due to the reluctor pick-up on teh crankshaft(you can buy the custom billet cover to run a dual roller cam, but the cover is about $300 by itself then you have to modify your reluctor). As for pistons, I would reccomend a set of the sealed power standard dished pistons for a 87-95 TBI engine. They have almost the same dish to them, and are MUCH cheaper as well as a quality piston(SUMMIT number STL-423NP--(whatever oversize you need)). For a long term engine I would stick with the 5/64 rings for durability. Also FEL-PRO makes a paper replacement intake gasket for these to get rid of the failure prone plastic ones(but the new VICTOR REINZ plastic ones now have steel inserts in them that seem to stop the cracking).

As for the trans, put a BEAST sunshell in it, a TRANSTAR HD torque converter, TRANSTAR basic towing rebuild friction kit, and a TRANSGO HD-2 shift kit, and a SONNAX E 1-2 accumulator housing. They really don't need much as I have torn into them with more miles tahn yours and they still oked good inside.