Look at the bypass hose in the front that installs between the water pump and cylinder head. If the hose is only about 1" long or so, it's a 170, if it's about 4" long, it's a 225.....or possibly a 198 that's been swapped in. Also, behind and under the alternator, there's a "shelf" of the block that sticks out that has stamped numbers in it. That will have the engine size. Something like "R225 *** or some such. You'll have to scrape it clean to see them, I am sure. Easy to find, just follow the cylinder head down until you find the joint where the head gasket is. The shelf will be sticking out.
