im building a buggy from scratch and was wondering if there is anywhere that lists the bolt sizes for parts on the chassis, example drive shaft to spring plates etc 

A good question that, you may find the answer on a dune buggy supplier in the states web site.

body bolts are 8mm length depends on body, seal and any reinforcing fitted can be stainless.

axle arm bolts are 12mm X 45mm with a 20-25mm shank on.
shocker bolts are 10mm X 90mm but need a 50-60mm shank on.
the shank is bare bolt so the threads are not in the casting or tubes.
M8 hardness if fine for all

don't think it would be cost effective to buy a doner beetle for nuts an bolts ive not touched an air cooled before so its all new to me!
thankyou for the info, got a feeling i'll be asking for many more sizes

They are mechanical simplicity but no 2 are 100% the same and bits differ.
there may be a local nuts and bolts supplier down your way to save all the postage unless you bulk order.

As Snoopy has said,  its all metric and M8, M10 and M12 is used all over,
the shanks are  standard length in most cases, though it will be ok to use a fully threaded shank too.

8.8 stamped heads, High tensile will also be the ones to go for, specially in the suspension areas.

The metric system is so easy you will have it down in no time


Peter

handy to know they are metric, you guys are full of useful info, snoopy by axel arms are these the 6 bolts which bolt to the spring plates from axel tubes?
thankyou again

they are you also need decentsflat washers on them( rather than the el cheapo wafer thin ones) and lock nuts or spring washers and bare nuts.

handy to know they are metric, you guys are full of useful info

Don't forget where it was made..... Germany

I work in an environment that uses bothe the metric and the imperial system, some
of the guy's 'won't do metric'.....

Which is amazing as metric the simplest most straight forward and adaptable thead system
ever devised 

Peter

thats one thing I don't want to use (although im on a budget) is cheap stuff to cut corners

Never get cheap stuff, just get the right ones.... Saves a fortune in the end too.


Plus, the right stuff doesn't cost that much more anyway, sometimes its just the ease of
ebay and the constant need to by something cheap that many will be doing...


With this stuff though, the standard is the 'thing', and its got to be right!


Peter 

You could do worse than a trip to Screwfix and stock up on a range of sizes and lengths, nuts and washers. While there get some storage boxes to put them in and write on the box lids what is in them.
I find it invaluable to have clearly labelled boxes, washers, nuts, bolts M6-8, bolts M10+ etc.

as Peter says, dont use stainless everywhere just cos its shiny

Really Important are the four bolts that hold the beam on.
They have a fine pitch thread on them although they are large diameter, DO NOT try and force the wrong pitch thread into the captive fixing and if you do have the right bolts don't over tighten them either. and if I remember correctly, on the covers for the spring plate doughnuts use 15mm headed bolts so you can get a spanner on em without having interference from the turned edge of the cover, if I'm wrong Snoops or Peter will put me right

H

my only worry really is the lengths and if they need unthreaded shafts, I bought my beam bolts off ebay with high tensile strength, then wondered as im having sway aways welded in ive notice shims but have no idea what they are and as ive got standard length will I need shims and longer bolts?

you only need castor shims if going lower than an inch or so but big wheels on the back also reduce castor.
the acid test is after turning left or right release the steering wheel and it should self center but many buggies and lowered vw's do not.
https://www.google.co.uk/search?q=beetle+caster+shims&client=firefox-a&hs=8hw&rls=org.mozilla:en-GB:official&channel=fflb&tbm=isch&tbo=u&source=univ&sa=X&ei=18opUtCHE4T17AbY2IFQ&ved=0CFsQsAQ&biw=1024&bih=625
vw also used imperial size fittings on beetles to help confuse matters on a car from a metric country.