Ive been having some trouble with my engine lately and we've considered getting a new engine put in. I know almost nothing about engines. Right now Ive got a V6 in my 4Runner its a stock engine. I have 33x10.50's and a 3 inch lift on my truck. Would I benefit from getting a 4 cylinder engine or possibly a diesel engine or just stick with a new V6? Can a diesel even fit in an 88 or 89 4runner? Im looking to save gas so thats why Im asking and I didnt know what would be best for me. Any help would be great. Thanks