[67Poncho]

I was talking with a friend the other day about the 390 install in the Cougar and he mentioned that I would need a set of "GT" heads to make this work. The 390 I have is from a 67 Thunderbird. I was hoping for a straight over swap. Any comments or experience with this?

Thanks in advance...

 

[Mercougar67]

Technically, every 390 head in '67 is a GT head. There is no difference between this t-bird engine and one that sould have been installed in a GT anything in '67 relative to the heads. Some casting had smog ports if they were manual trans cars or cars delivered to California. My advice: Install a cheap used Edelbrock Performer RPM aluminum intake manifold and a set of reproduction 428 CJ exhaust manifolds, slam it in and drive it. DONT put exhaust manifold gaskets on the exhaust manifolds. Don't over-carb the engine. Install a new 600 CFM Edelbrock Carb. Edlebrock carb......not a Holley. The new Holleys are vastly inferior to an out-of-the-box Edelbrock carb. Make sure you have a new, replacement gas tank in the car or this whole swap will be junk in a year.

 

[CougarCJ]

I think that your friend meant that you will need cylinder heads with the extra holes for mounting the exhaust manifolds.
Typically the 390GT heads had 14 bolt holes for the Cougar exhaust manifolds, and 16 bolt holes to install the 428CJ exhaust manifolds.

 

[xr7g428]

Whoa there boys... The location of the bolt holes in the head for CJ manifolds are not the same as GT manifolds and GT manifolds require additional holes as CougarCJ pointed out. The key thing is to decide which manifolds you are going to use and to get the heads drilled accordingly.

I would second the CJ manifold recommendation. Carb wise, my favorite for the 390 is the Holley 3310. The fuel inlet and everything else is a where it belongs, and ALL GT motors came with a Holley. Probably the best choice is the one that you are most familiar with tuning. Any carb poorly adjusted is going to run badly. If you have to pass smog inspection I would go with the Edelbrock as it has a lot more range of adjustment than the Holley.

 

[sportyworty]

or run a set of headers and run whatcha brung...no drilling required

 

[67Poncho]

Thanks for the replies. I have a set of brand new headers that I picked up in a trade but don't know if they will fit untill I get the motor hanging in the engine bay. All I was told was that they were for a 390...if they don't fit I will probably try the exhaust manifolds from the tbird and then go from there. Now that I think of it I may have access to some 428 CJ parts ie heads, ex manifolds, intake, crank...

Thanks again, Gerry

 

[sportyworty]

Gerry
The T bird log headers will not fit in your chassis don't waste your time. See if there is a part number on your headers and post it. If you need some I have a new set of Hooker Super Comps that are for 16, 14 or 8 bolt Mustang/Cougar they were installed but never run. If you have an interest I will give you a great deal on them. 300 bucks plus the ride. BTW my Dad just moved from 100 mile house to Kelowna area. He said it was too cold ranching up where you are any longer lol

 

[67Poncho]

Okay thanks for the heads up on the manifolds. The headers I have are stored in the trunk of the parts car which is buried under 2 ft of snow...I'll see if I can dig them out today. We had a long stretch of -20*C and colder temps this winter, wouldn't blame him at all for moving. I was working out in it until about 3 weeks ago and finally had enough. Quit work and came home to get back on some projects around the house...