JR is right about his post and considering if its rod knock each one of those *CLANGS* is the rod hitting the crank at anywhere from 12- 36mph. Yes I actually did the math to figure that out
. In anycase a lb or two going 25mph hits pretty hard , chances are there is crank damage. The rods in these things are forged, so hopefully they're salvageable because they can get pricey. All the damage really depends on how long its been knocking and how hard it was driven during that. Even with knowing that, there is really no way of knowing you really just have to get under there and check it out. Expect to pay $80-120 for the crank regrind and $10-20 for each rod, put that amount + 1/4 to the side and if you don't have to spend it its gravy for later. Then you have cleaning cleaning and more cleaning and finally add $5000 for unexpected parts, labor, and court costs. hahaha ahh my poor car.... but anyway yeah much of the work can be done yourself but I'd suggest handing everything over to a shop (after you clean the hell out of it) for a few days and letting them take measurements to make sure you're not going to have a problem once you have it back together. It'd hurt if you put it back together and find out there is too much clearance from the rings to the wall and now you're filling the oil every time you fill your tank. Also definately have that oil pump checked out. Mine came out perfect and we didn't need the new one I got, and thats after 109k miles and 5-6 bottles of nitrous and being beat up and redlined every time I drove. Amazing the punishment these things could take. If I've learned one thing from my experience its to take a good close look at any warranty info available. Probably since I guess you plan on doing most work there won't be much of any but say you take your crank in for a grind, have him sign a piece of paper that says "I ground '* crank to ## under" or something like that. Just incase, ya know? Don't end up like me and pay nearly $4,500 for a rebuild. Although something tells me after this last one I'll enjoy every penny of it and in some way it'll all seem worth it. At least thats what gets me to sleep at night.