Is a ford 390 better than a 351w?

I got a 79 f150 with a 351w and i have a 390 in the garage would it be a good idea to swap it for more power

An EEC IV injected 351W is light years ahead of a 390.

Rebuild the 351 cheaper to do and you can make more power cheaper, not to mention it is lighter

The 390 is a 'small' big-block engine while the 351W is a 'big' small-block engine. If you swap in the 390, you'll need a different tranny. Plus, there are many more upgrade parts available for the 351W. I have a 351W in my Mustang that has be stroked to 427, so upgrading the displacement is not hard.

The 390 has a.028" longer stroke… That's going to parlay into about an extra 50-60 lb/ft of torque if you're towing… BUT it comes at the cost of a transmission swap since the bellhousing doesn't match. DEpending on the year of your 390, you might be looking at 9.5-10 to 1 compression. If there's no towing involved, I'd stay with the 351W. The 390 is about 100-120 pounds heavier, but you're not using the truck as a sports car, are you?

What you need is a new truck, just how long do you expect a mechanical item to last? Plan on having it be your grandkid's inheritance after your kids pass of old age?