Is your truck running the stock 6?
If so, just buy the parts from Toyota and bolt it all on. Very simple job. Hardest part will be getting the bolts loose from the exhaust manifold. Or, buy an aftermarket exhaust from SOR.com or from man-a-fre.com
If you have a V8, it's not that simple. However, you can make an exhuast system yourself. Get a set of Rams Horns style manifolds from A1 auto on ebay for about $60 each, then get the correct cross over from a mid 60's GM Pickup. You can then bolt it up to an off the shelf system from downey. You may have to have the pipe tweeked by a muffler shop to join the two, but I did not have to, but this should be bolt together if you can find the correct parts off the shelf regarding the "Y" pipe from a mid 60's GM truck. Takes time, but is worth it.
74's are an oddball year, cool truck.
-Stumbaugh