To the best of my knowledge the wheel openings are the same, I am going by the use of repair panels from the past.

I don't know if this is any help but might be worth a look, lower rad hose for a 65 Galaxie has the bigger end for water pump

Almost Identical to my 390

I forgot to mention that the lid of the breather also has a rise in it between 1/2 and 3/4 to where the wing nut is so you will likely be ok look at  the pic of breather top. All the best

I started off with a 410 with the intention of just upping the cam. When I decided to go the 445 route and build a serious engine I swapped my disassembled engine with a buddy for a 390 block, Street Dominator intake, and a few bucks.

Now the bad news, the block has been taken out to 4.08 and in one cylinder there is still a little rust about an inch below the deck. You can just feel it with your finger nail, each spot is between 1/8 and 1/16 of an inch around, and there are a couple of them. The machinist feels you could build a more or less stock engine and it would run fine, but knowing what I'm doing he said he wouldn't.

My buddy will give me back the 410 block, and it was already about 4.07, and it would go 4.08 without a problem (we measured them before we swapped).

He also has a 390 GT block with an "X" cast in the lifter valley (or the end of the block, I don't recall) that he thinks indicates it is a high nickel content casting. This block has already been bored out to 4.07. He is of the opinion that because he has all the original parts including adjustable rockers that it is a valuable engine.

This leads to a couple of questions:

• Is the "high nickel content" a myth or is it real?
• How do you tell?
• What difference would it make (as in, should I lean on him to get it)?
• Last, I told him I didn't think an original 390 GT was considered a rare or valuable configuration, is it?

My understanding is that an original date code correct 390 GT was only worth a little more than a standard 390 today, but a high nickel content block might be interesting.

Just my 2 cents worth quoted from High Performance Ford Engine
Parts Interchange
by George Reid

360/390/410
The 390 block doesn’t differ much from the 332/352/361 blocks of 1958-60. The 390 uses the
same block as the 360 and 410. All share the same 4.05-inch bore, with displacement varying
according to stroke. The only real difference here is the crankshaft. The 410 Mercury is a 428
crankshaft in a 390 block. The 360 for trucks is a 352 crank in a 390 block. Where this block varies
at all is in the area of high performance applications. The 1961-65 390 Police Interceptor and High
Performance blocks (C1AE-V, C2AE-BC, C2AE-BE, C2AE-BR, C2AE-BS, C3AE-KY, C3ME-B, C4AE-
F and C5AE-B) have heavier main bearing caps and drilled oil passages for hydraulic lifters. The
trick here is, Ford never drilled the oil passages from the main galleries to the twin lifter oil galleries,
which means no oil pressure to these galleries. Hydraulic lifters cannot be used in this block.
Another difference in the 390 Hi-Po block from 1961-62 is additional ribbing between the main
bearing webs. Ford also added an oil pressure relief valve to the block for added protection on the
390 Hi-Po.

I have a 1966 7 Liter Galaxie with 428 and power steering. With the help of my mechanic buddy, I added the '65-'67 427 cast iron headers quite a few years ago. They do fit. A couple thoughts I'll throw out there - when we did it the car already had the power steering installed, is it possible you need to take a header off first to install the power steering gear box? Where exactly are you seeing interference? We also installed NOS rubber motor mounts at the time of the header install to be sure sagging motor mounts wouldn't cause an issue - are your mounts in good shape? I looked in the Ford parts book, it looks like Ford used 2 different power steering gear boxes in the '65 to '68 period - a Saginaw box and a Ford box. They can be I.D.'d by the code on the tag attached. I don't know how they differ, but it's possible one works with the cast headers and one doesn't? Unfortunately my car is stored away from home so I can't immediately take a look at anything.

Thanks for the reply.

Believe it or not I am a mechanic , I did realize there were two different boxes used in these. The Ford box has a two bolt flange that holds the sector shaft and adjuster, where as the Saginaw box has a four bolt flange and is quite often aluminum and I do believe the sector shaft in the Saginaw box is smaller diameter. I was trying to install the Ford box because I had one complete with pitman arm. The engine mounts are in excellent shape but the ford box hits at the top rounded edge of the sector shaft plate about centre where the divot is cast in the header and will not allow me to align the mount bolts. I bought the car with these already installed on a rebuilt 390 but has manual steering after trying for 2 days almost without removing the header I just went back to the manual box as I didn't want to remove the header. the headers are well sealed and I didn't want to disturb them and risk breaking a lug off or worse. The headers are in perfect shape as best I can tell without taking them off.

I was wondering if there was a possibility of a Saginaw box needed to do this. 
I have searched about all I could to find a good pic of them installed on a car but that is more rare than an original 427 in the same car.
 Thanks again.