Pick a 390 over a 360?

[Damon555]

Going to drop a motor in the old '69 and was wondering if there is anything to gain by putting a 390 in instead of replacing the 360? Other than a gain in power will the fuel mileage be any better? Since the truck is a 3 on the tree can that tranny handle the added power of the 390? I'm going to make this decision pretty soon....I appreciate your input!

[85e150six4mtod]

3 speed will handle it.

Even if you replicate the lo-po PU motor 390, it will use no more gas for the extra power. If you bump the compression to 9 or 9.5 and otherwise keep it conservative for cam and carb, and put headers on it, you will gain power and mpg. (no miracles, but think 10-15 vs 8-12 for example)

[backwoodsgoop]

360 i would say there a great eng and I would wonder about the three speed I blew a few up converting to a v-8 but it was a chevy I have since wised up go with a good old T-18 0r 19 or c-6

[85e150six4mtod]

Originally Posted by backwoodsgoop

360 i would say there a great eng and I would wonder about the three speed I blew a few up converting to a v-8 but it was a chevy I have since wised up go with a good old T-18 0r 19 or c-6

360 a great engine? Great?

And the Ford 3 speed behind the 360 is the same as the one behind a 390, so it will handle the 390. The same 3 speed is also configured for sixes, but that's not the case here.

[johnboy427]

The old 3:03 spd is very tuff, it is the same design as the toploader 4spd and some say the 3spd is even stronger because the counter and main shafts are shorter. I beat on one for years with a pretty stout 390 and it never gave me a lick of trouble.
-Johnboy