hi leon, $500 is a lot but even with propper tools id reckon it would still take a while to do. if you have yourself a dremel or air die grinder you can do this a lot easier if not then grab a drink and read on
first and the best tip i can give anyone is unless you are entering as an elite in any show
ONLY POLISH AREAS THAT ARE GOING TO BE SEEN & SPEND MORE TIME ON AREAS THAT GET SEEN FIRSTi initially got that horrible orange baked on plastic like paint sandblasted off, even then not all of it came off.
then got myself a couple of wire wheels ( ones that mount onto your drill) and hit the manifold with these., they got the rest of the paint off eventually but you will find they dont reach in all the places, but they also started to knock back some of the texture of the casting which is a good thing.
next i grabbed some 80 grit paper some beers and some decent music and started sanding. after a couple of weekends at this stage i realised that a cheap pair of mechanics gloves will stop my fingertips from being cut back and blood getting everywhere. skin does not like constant contact with 80 grit
:-/ they also helped on cold canberra winter days.
as with polishing any alloy you just have to work your way through varying grades of paper, i found the hardest part of this job is really only the first 4 grades, 80, 120, 220, and 400. these took a good couple of weekends but went through the final grades ( 600, 800, 1200 then finally 2000 ) in about 6-8 hours.
before i went too far i cut the EGR port from the base
( this is not needed ) and got someone to weld up the hole. also if you are still going to run carbs with the supercharger check and see what holes you will need to use on the manifold and get the ones you dont welded up.
you can also grab yourself one of those little engraving type tools from supercheap only around $20- $30 which comes with a range of attachments and will let you get into some of the fiddly areas.
the castings on these manifolds is really poor, even on mine there are bits that look very much like wrinkles.
and finally if you have a bench grinder grab yourself some buffing pads and finnish the job off with these. make sure you wear some decent safety galsses and a dust mask, as crap will go every where. if not you can get smaller buffing wheels that attaches to you drill.
i guess there is no real easy way to do this unless you pay someone but it having the right tools ( not like me) does make it simpler but after all this hard work they do look sexy when done
but as i stated before apply harkos rule and you'll be suprised how much you can get done.
i will try and get some pics on the weekend and show you.
good luck
dean