1968 289 or 302 block

[Mosesatm]

The '68 302 heads are highly sought after because they have larger intake valves (1.78" vs 1.67") and much smaller combustion chambers (53.5cc vs 63cc) creating higher compression (10 vs. 8.7) and more power, but premium fuel is recommended. These heads were used on Shelby GT350s so the Shelby guys snap them up when they can. If you can find an inexpensive set grab them!
http://www.mustangtek.com/heads/Heads.html

 

[CougarCJ]

Adding to what Arlie said.....

The 1968 302-4V cylinder heads came two ways, with or without thermactor holes.

 

[Jester]

Always amazed of the knowledge you find here! I have had some thoughts about an upgrade to a 4v carb and intake for my c code. Haven't decided for sure yet as it is a just newly renovated matching numbers original engine. (Apart from a dual exhaust added a few years ago) and i kind of like the historic touch. But at the same time I can't let go of the feeling it doesn't quite give me the kick in the back I'd like. Anyways if I were to do this I thought it might be fun and interesting to do an upgrade with period correct CS Shelby upgrade parts. Have looked around but don't find much. Anyone knows if there are reproductions of CS Shelby intakes and aircleaners? I guess the Shelby intake was used with Holley carburetor.. Is it a feasible route to take or is edelbrock 289 intake and a 570 edelbrock carb a better way to go? Thanks for any guidance.

 

[franklinair]

I've had good luck installing an Edelbrock Performer 4V intake with an Edelbrock 500CFM electric choke carb. I grind off the Edelbrock casting name, paint the intake engine blue, and it all looks stock. Improved performance, and with your already installed dual exhaust, you'll be happy.

Neil

 

[CougarCJ]

I like the old Edelbrock F4B intake, and intend to install one on my Cougar eventually.

Cylinder head wise, I would go aluminum and paint them Ford engine blue so they don't stand out.

I can't recommend a cam, that would allow the rocker assembly to fit under stock valve covers.

 

[Jester]

Neil, is that the low- or high rise performer intake you have installed?

 

[franklinair]

Low rise, and using a 1" phenolic carb spacer.

Neil

 

[x-codegtcs]

The 289 C code heads (289 and 66 cast in the top) you have are a 54.5CC chamber...enough clinch for today's gas and only 1CC larger than the j-code heads. It is the ports that are choking the motor. An intake may make some difference, but in the end, the exhaust port only allows so much out the back door. If you want to really open up the motor, CougarCJ is right about the aluminum heads - ports and valves - tastes great, less filling. Even if you ported the cast iron heads, they still can't touch the flow rates BUT they would be original.

My understanding is the original Cobra intake was nearly a mirror image of the cast iron 4V (289 or 302) intake...just aluminum and was only put on when sales suffered because people wanted the GT350 to have some marked difference over the standard Mustang. Aftermarket intakes are better. Intake selection depends on your cam as RPM power band would affect what intake would be best.

 

[CougarCJ]

Both the 'Cobra' and 'Shelby' versions of the 289/302 intake manifolds were cast by Buddy Bar, and resemble the Edelbrock F4B intake. All three have tall runners, compared to stock Ford cast iron 4V intake manifolds. I will try and find a comparison photo.

 

[Jester]

I dont find any CS Shelby intakes when searching on Internet, only cobra, are there no new reproduction of the CS Shelby intakes and aircleaners? It would be fun to use the CS Shelby intake and aircleaner as after what I understand it was what was on the market back in 68. But at the same time I will still do large changes to the stock set up so maybe it doesn't matter, I will keep all the stock parts anyway and will be able to go back to stock if I feel the need. The edelbrock 2121 intake and edelbrock 500cfm carb seems to be the easier way to go as parts are available also in Sweden. I assume also the parts will work and fit together beautifully. I agree with the exhaust bottleneck and it would be nice to change the heads but I will not have the money to do it all at the same time. I will need to start with intake, carb, aircleaner and pertronix ignitor and then follow up in a year or two with the heads. Just important I don't build myself into a corner. With the intakes we discuss here I assume they must fit pretty much any 289/302/aluminium heads...?