Thanks for the compliments Doog, glad you like it. Yes, the suspension needs to be lowered if modeling it with an engine. Here is a tweak list to improve upon it. Not all the tweaks need to be done as most are cosmetic, but I would at least change out the tracks with the AFV Club set.
1. Turret height should be increased by approx 1.5mm, which can be done by adding a sheet styrene shim, which can then be sanded to the turret's shape.
2. Fill the motorization slots and holes on the model.
3. Three oval holes should be added to the drive sprockets at the 12, 4 and 8 o'clock positions, these are not present on the model, but were there in real life. Check reference pics for shape and location.
4. It's worth considering replacing the fender stays with PE items or homemade efforts of very thin sheet styrene.
5. Rebuild the stowage basket from thin wire; it really improves the model.
6. Add casting numbers to the turret roof, rear hull, and engine access doors.
7. Glue mantlet in place and fill gap with milliput to represent the canvas cover.
8. Replace the cover, fixing clips with plastic strip and add bolt heads.
9. If shown opened, shave off loader's hatch internal handle and latch mechanism, and replace with brass or plastic strip, rod and tube. The same should be done for the exterior handle as well.
10. Turret water jerry cans have incorrect style filling cap.
11. You could replace the molded on tie downs on the turret with brass items.
12. Use copper wire to add 3 lifting lugs to the commander's cupola, at the 12, 4, and 8 o'clock positions.
13. Shave off and replace the hull stowage bin handles with plastic/brass strip.
14. Fill up the main turret site periscope, as well as the driver's periscopes.
15. Add cast texture to the turret and hull.
16. Replace the awfully incorrect kit tracks with aftermarket ones. The AFV Club set is great, just make sure you get the correct one, they make two sets that they say can be used on the M48 and M60 tanks. One of them has octagonal shaped pads; the other has chevron shaped pads. The latter (chevron block) are the correct ones for a Vietnam era tank.
17. Suspension height correction. The Tamiya kit was based on a vehicle that did not have the engine installed, as such, it was lighter and rode high on its suspension. The kit is about 3mm too high. To fix it, cut the tabs off the road wheel arms and lower all the arms by 3mm. Each suspension arm damper should also have about 2.5mm removed, they are too long and also make the model sit a little too high. You may also have to remove a couple track blocks on each side to take the slack out of the track.
Good luck and I can't wait to see yours.