350hp can be done with your heads, increase valve size to 1.94 1.60 really spend some time on opening and blending the valve bowls an making a smooth transition into the ports, the intakes just need a good pot match but the exhaust is what needs the most work, it can take 20-30 hrs to do a nice port job by hand on windsor heads and thats if you know what you are doing and with a good electric die grinder like a makita and about 10 different shaped and length carbide bits as well as sand rolls. If you have never done it before and dont have the tools on hand you are better off buying aftermaket heads, even gt40, gt-40x, perfomer heads can be found for cheap as factor in buying the die grinder,carbide bits,sand rolls etc can set you back 200-400 bucks, dont forget hardend ex seats.
Cam will depend on rpm range,compression, gears etc.....a hyd roller will give the best power vs hyd flat tappet but a solid flat tappet gives killer power as well, if you want to run a cam with more than about .480 lift or run roller rockers then you will have to have your pedistals machined/tapped and install screw in studs and guideplates, if not you should stick with the old high energy or a small xtreme energy cam and dont even consider a hyd roller or solid cam. See what my point is? by the time you port, machine,valve job,hardened seats, valves ,springs,screw in studs, guideplates etc....you could have bought new alum heads for cheaper, I'm no a fan of them but with some work the chineese pocomp heads (vic jr copies) can work well for cheap an with alum heads the 400hp number can be done with a much milder combo than the 350hp iron head home ported combo. Rockers. your choice and how much p/v clearance you have, in some cases a mix of 1.6 an 1.7 work better but most use 1.6, redline can be anywhere from 5000 to 8000 depending on your, cam an the rest of the combo, usually a mild build will stay under 5500.
Bottom line is what do you want it to do? how much do you want to spend? I went from a 289 to two diff 351w builds to a 408 and now I'm thinking about upping my 500hp to about 650-700 with some n20.
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