NO. Look up GM diesels for Oldsmobile and find out why. Bottom end is not strong enough, heads are all wrong. NO.

 

The cylinders and block is EVERY modern gasoline engine will be FAR TOO WEAK. That's why a Duramax diesel engine weighs 835lbs

 

Short answer is no. Long answer is yes, but WHY?
If you want a french fry oil burner get an old mercedes diesel or VW diesel and set it up to go. It will turn out good without a lot of money.
The project you are talking about , converting a gas engine to diesel would be costly and ardouos at best. Then you have to find and injection pump to run it. After all that much work and cash, i wouldnt be dumping in any dirty old french fry oil.
Find a diesel engine and adapt it to your buick, or adapt the car it is in to burn the french fry oil.

 

Olds also made a V 6 version of the crappy diesel engine. Pretty rare.
They are pretty much all gone by now, I am certain.
I did see that there are guys using the 350 diesel blocks to build hi performance engines. they can handle lots of horsepower because the castings are heavy/strong.