Hi all,

the engine is 289 from a 66 Mustang (at least to what the engine casting number says).
The datecode confirms. I guess the block is the same anyway, but they have different compression.
So for that I guess there are 2 types of heads.
Is there any way to figure what compression ratio (what head) I have without poulling it?

 

Not sure about the compression ratio but...

is it just the short block or is it complete, A codes came with 4 barrel carb, C code with 2 barrel. I thought the A codes were supposed to be ~10:1 comp, and C codes ~9.5:1

check this site

http://www.carmemories.com/cgi-bin/v...erience_id=131

 

engine is complete. currently 2barrell but I know the PO ran a 4barrell on it.
But thankls for the link. it says that both the A-code and C-code had a comp ratio of 9.81:1 in 1966
So that answers my question

thanks !

 

If your car is a factory A code it will have an A in the VIN number, 4th or 5th digit I believe. Same for a C code.

 

Compression change is actually from different pistons, not different heads. There are no 2V or 4V heads. The only way to tell would be to either look at the VIN on the original car, or take it apart and inspect the pistons.

 

check the VIN, based on the numbers produced though it is most likely a C, but you could have an A code, check your VIN

 

....this isn't the original engine for his car.

 

missed that part

 

yah. sorry. should have pointed that out more clear.
car is U or F code. don't remember. 170ci 6 banger. engine is 289 from 66

But as all the 66 289s are same compression ratio the only difference seems to be the intake and carb .. which i'm going to change. I'll just wait for a few months, order a cam kit (the K31-234-3). I have a weiand8124 intake and a holley 570 already sitting on the shelf waiting to go in .. :-)
Usually i'd put in the carb and intake straight away, but I was not driving for 3 months, so all money is now going towards petrol :-)

 

sorry I didn't make the connection that that the engine was a 66 and the car was a 64.5

you said its two barrel but the PO ran a 4? does it have a 2 barrel intake then and the PO used an adapter? what intake do you have