Want to swap my 1975 318 for a 1977 360, any problems?

[1975Scamp]

I have a 1975 Valiant Scamp, want to do a motor swap form a 1975 318 to a 360 date stamped 1977.

1) Are there any issues with this swap?

2)Are there any years I should stay away from due to power reduction (horsepower)? I feel I have been given a good price to purchase, I just a little reluctant to pull the trigger to buy yet!

3) If I buy, can I pull the heads and install on 318 to improve performance until I have all the funds to fully go through 360?

Any input would be helpful!

 

[340sFastback]

360 heads will cause a big compression drop due to larger chambers.

You will need a 360 motor mount bracket for driver's side. Or shim the 318 bracket to fit.

Flex plate or torque converter may need weights to balance, not sure, maybe someone else knows.

Other then that its a direct bolt in.

 

[67Dart273]

Flex plate or torque converter may need weights to balance, .

Yup. Easiest way is to by a B&M aftermarket flexplate just for this situation. You'll want the one described as neutral balance converter, for 360LA (not magnum) to 727 trans. I believe they are about 89 bucks.

If you ever decide to go back to a 340/ 318, all you need to do is drop in a factory flex plate.

 

[rumblefish360]

Yea, that's the way to do the external balanced 360 to the neutral balance converter. Call up B&M to find out which one to get.

The motor mounts will require small diameter washers to take up the extra space. Or a metal tube. It is a small amount and small potato issue.

The compression drop from switching heads is right about 1 point. Not good for the all ready in trouble Lo compression 318. Your best bet for this 360 performance wise is a mild head milling to get into the 9.0-1 range and a cam swap. Add your choice 4bbl. and headers. You'll be good to go.

 

[1975Scamp]

Thanks for the input! If I have the heads mildly milled, couldn't I then install them on 318 til 360 is complete? Wouldn't that also take care of compression drop in the 318 or is the milling different?

 

[1975Scamp]

I have also been told that the later 70's motors the cam has been retarded for more fuel economy, is that any kind of issue? I just don't want to buy a boat anchor if on a 77 I will not be able to get the performance out of it!

 

[Dartnut]

Also, the oil pan is different on a 360 than a 318.
A truck pan and pickup is different than a car pan as well as the dipstick.
Is it coming out of a truck?