I have the Morris in my 71 with buckets. They are a direct fit with no drilling required. When we started a group buy with them I noticed the buckle end was formed incorrectly and did not properly fit the contour of the seat. After a couple phone calls trying to decide the best way to have the belt fitting right, they sent me several samples to try. I picked the best fitting buckle and this is what they are still using. They also replaced (with free shipping) all the belts others had ordered at the same time. These belts are the best fitting and looking of any aftermarket seatbelt I have seen. Plus it's a family run, made in the USA company. Great people to deal with.
I was so impressed with the seatbelts I bought the Clear Shot mirrors. I am equally impressed with the quality of those. After the initial adjustment I have never had to readjust again. Never had that with any other aftermarket mirrors.