thoughts on head swap for '65 200

[Anonymous]

this is a general question looking for a general answer-

i've got a 65 fastback with a 200. the car is 99% original and in incredibly good shape, but i'd like to liven things up a bit. i'm still in the early planning stages and wondering what sort of head swaps are possible. i'm looking eventually at upgrading to a 2 barrel carb, more aggressive cam, dual header, electronic ignition, anything to bump up the hp without radical modification to the block (the car's in good enough shape i don't want to compromise the possibility of a future back-to-factory restoration). i'm new to the hobby and understand the basics, but what should i consider? it will be a weekend driver and i'm not concerned about high-end performance or winning any races. just something respectable and fun with a little more punch. any ideas?

thanks

 

[Anonymous]

Hi Brady,
I'm pretty new here as well, but I'll chime in and suggest you get the Falcon Performance guide. Many here will swear by it. My copy is on its way.

What part of Atlanta are you in? I live near Decatur. I also have a 65 200. It's a coupe, though. Great cars, they last forever.

Scott

 

[mugsy]

There are the 3Cs of power: Cam shaft, Carb, and Compression. Plus the exhaust header and better ignition.

Head modifications will entail the last two C's. So here is what I learned when I placed a 250 head on my '65 Mustang.

Look for a late 70's ('78 and later) 250 head. It has the larger 1.75 inch intake valve (verusu the 1.68) plus the harden valve seats. I found a '77 head and it had the larger intake valves and harden seats .

The combustion chamber is larger on the 250, you will need to have it cc'd and then shaved to get the compression you want/need. Plus the typical replacement/aftermarket head gasket is thicker than the stock/OEM steel shim head gasket. But this is critical, you must measure both the deck height and head cc and adjust accordingly. I had the machine shop take 0.030" off the block for a zero deck height and 0.040" off the head to get the cc's I wanted.

If the head or block is milled then use washers under the head bolts. Make sure you have adjustable rockers too. My '65 head had then originally.

The 250 head I found had a larger t-stat housing, so you will have to use the original 200 housing. Bolt pattern is the same.

The 250 water temp sender has a smaller post for the wire and larger thread than the '65 one. So the OEM wire/connector will not slide on properly. So either put on an new wire connector or use an NPT bushing on the threads.

The carb on the 250 head is larger diameter bore AND bolt spacing. Not an issue if you are changing to a 2 bbl. But you can not use the 200 carb on the 250 head without an adapter or other modification.

Before you put on the new head, buy a die grinder and clean up the casting flash and other restrictions in the head. Also gasket match the exhaust to the header.

tanx,
Mugsy

 

[Anonymous]

thanks for the info so far...

scott- we're in tucker, but i work in decatur...

 

[Anonymous]

You don't have to swap the head. You could start with some of the things you listed and do the head later, if you wanted. You could change to electronic ignition, add headers, a two barrel etc. without modifying anything that you couldn't switch back to stock.

Good luck,
Scott

 

[Anonymous]

If you have the $$$$, talk to oPhil aka ausheads. He has 2V aussie heads that have a removable intake that will accept a 2V carb. Best of all they will bolt right on your block.

I know alot of the guys will disagree with me but I think if you are looking for real performance the log head is a waste if time. Aussie 2V's, Crossflows and the Argie head are a better place to start from. IMO