Wha
You really need to tell us what you are working with.
Make, model and year.
It is a 1967 Plymouth valiant 2 door with a previous slant 6. 3 speed
t was in your car before. A 318 or 360 will go in perfectly as with a 4 speed. Did your car have a slant six, was it manual or automatic transmission. Give us details of what you have then you’ll get more answers than you can handle.