Is the only difference between a 360 and a 390 the intake manifold?....any info??

 

... a difference of 30 cubic inches achieved with different crankshaft and rods.

What prompts your question?

 

Well i have an opportunity to purchase a 76 with a 360 for $300..I was looking for a 390 motor and i was told that all i had to do was put a 390 intake on it..that was the only difference between the two motors....if i got the truck i would strip it down for parts...

 

As I understand a 360/390 has the same block, you would need a crank, rods at minimum, likely also a intake, carb and may as well put new pistons and everything else while it's apart?

 

The crank and rods are the ONLY difference between the two. Same everything else. The 360s use the flat top 4v pistons from 60s 390 cars. They may be recast as something else but they are essentially the same. These will give a CR of 10.1-10.5:1 depending on the rest of the stack. The 390 2v pistons have a small dish and will get you 9.2-9.5:1 CR. So you'll probably need to get some 2v pistons to run in a truck, if you don't change cams then it's a must. Otherwise you'll have detonation problems because the dynamic compression ratio will be too high.

360=4.05"bore x 3.5"stroke
390=4.05"bore x 3.784"stroke

 

Yea something sounded offf when he was giving me his sales speech...

 

That's the first thing most FE newbs learn. "All 360s become 390s on sale day." lol Without measuring the stroke there is no way to tell them apart. This is a new one though. Just swap the intake to add 30ci.. Some people will tell you anything.

 

Cool, I just learned something new!!

 

i learned that too when i bought my truck, but im not so shure the guy i bought it from knew what it was or not he told me it was a 360 and ended up being a 390 when i tore it down