Go to:
www.amkproducts.comClick on 'PDF Catalog', and study pages 1-5. Next, study page 198, in particular part numbers C-8050 and C-8051, 383 water pump kits at the bottom of the page. You can either buy those two kits for $26 or try to decode what is in them.
You can compare the existing hex bolts you have by figuring out their diameter and threads/inch and comparing these to the Hex Bolts section on the PDF Catalog from page 9 - 24. As you look as these, you will quickly find "Chrysler Carburetor" bols on page 9, "383 Distributor" on page 10, "383 Water Pump" on page 12, etc.
Even though your car is 1970, you might get some help from the Chrysler Corp. 1969 RR 383 engine assembly shop drawings from Faxon Automotive Literature. These drawings show the Chrysler part numbers for the engine 'dress' bolts. 'Engine Dress' means adding parts like the carburetor, fuel pump, A/C, PS, throttle cable, engine-transmission linkage at the assembly plant, not the basic engine that was assembled without a VIN at the engine plant. In other words, the Faxon drawings will show how the A/C compressor was mounted, but they will not show basic parts like exhaust manifold bolts. The AMK catalog has some Chrysler part numbers for bolts indexed on page 405.
The AMK catalog will not be exactly accurate as to the maker's mark on the top of every hex bolt for every car, because Chrysler had so many fastener vendors. But the bolt size for any particular use should be accurate.
Be sure to understand the difference between 'hex bolt' without captive washer and 'hex machine screw' with captive washer categories in the catalog. You'll find fasteners with captive washers for oil pan, valve cover, crankshaft pulley, and K frame fasteners listed under 'hex machine screw'.
