big block head swap
 

I have a 1964 361 big block. I found a set of 1969 906 casting heads and was wondering if they would fit. From what I have researched any big block heads should fit, but I wanted of your guys opinions!


Thanks for the help!

Yeah scott, they will fit,with that small bore it will need more cam.

They will bolt on just fine. The 906 casting are an open chamber head with larger valves. Your stock heads will be of a closed chamber design with smaller valves. You will lose some compression and some low end torque due to the larger valves. If you were going with higher compression pistons i would say they are good swap. But if you building a performance motor I would recommenced going with a 383 or 440. The heads will bolt on fine and the engine will run good but it might just lose a touch of bottom end power and maybe pick up just small amount on the top end. Not a huge difference if you are looking for picking up performance. If you just need a new set of heads because your heads are worn out or damaged then they will work good.

What cam would you recommend with those heads. I have a 64 dodge 880. Its a cruiser so I don't want anything too aggressive, I'm also considering headers, and a 4bbl carb.

I dont think putting a larger cam will do any good. If you are putting on heads the lower your compression and then adding a higher profile camshaft you will loose way to much bottom end to make this a fun car to drive.

I want to use the 361 thats original to the car, and I'm working on a budget, so what do you guys recommend as far as engine upgrades! Its not a hotrod, but I want it to have a little get up and go when I hit the gas!

Headers and a 4bbl carb will wake up the motor a bit. Go with an edelbrock performer or a stock 4bbl manifold. I like edelbrock 600 cfm electric choke for that application. Cam I would stay with a stock or if you want a bit more go with a stock 383 magnum cam.. large cams will bleed down cylinder pressure at low RPMs and that is not good with an already low compression ratio and a relatively small motor for your heavy car.

I am definitely wanting low end grunt! I want it to have some balls from stoplight to stoplight. I'm not wanting a 12 second 1/4 mile car, just a solid performer. I don't want to spend a lot of money either. Do you think swapping to a 906 head would be beneficial, or should I stick with the original? I believe the factory CR is 9:1

915 heads are a large valve closed chamber. But as they are a 1 year only(1967 440 magnum) head a bit hard to find. You could have the 906 heads milled some.

I think for your set up, I would stick with stock heads. I do not think there is much power to had with 906 heads for your combination. you could have them milled and it would help but still would not do as well as your stock heads. The headers and 4bbl carb will give what you are looking for with out breaking the bank and ruining the driveability of the car. You could do more things to make it faster but it will cost more money, and make the car less of a pleasure to drive on a regular basis.

Intake, carb, headers,and gears.

What gears would you recommend? Switch out rear ends or just gears? Will that throw off my speedometer and if so, how do I correct it?

With out knowing what you have it is hard to tell. I would figure on some 3.23s or 3.55s ...you can change the speedo gear in the trans to match the gears.

You can put 4.1 to 4.56s if you want and you will definately improve accelleration but you will make it not as fun to drive on freeway.

This would be a good set up and the 383 magnum cam should work well.
If you're on a budget, just the intake manifold, carb and exhaust work will make a difference.

You said, "I have a 64 dodge 880."
I believe this to be a c-body, no? You are going to find it hard and very expensive to get good headers for this application. I would suggest you find some c-body Hi Po manifolds or just go with a good dual exhaust, off the stock logs. Have you done a good tune up? It makes a difference, and will establish a base to go off of. A small 4 barrel and stock type intake will help make torque. This is what you need to get a big car moving off line. You should talk to the cam manufactures, they can set you up with a nice torquey grind. If you want to swap in a cam, get springs and lifters as well. I would just do the 4 bbl and duals first, then maybe an electronic distributor, and change the cam later. Install each, one at a time to see how it helps. The fewer things you do at one time the less aggravation later if there is a problem. It's just me but I would not change rear gears until you get what you can from your motor. You can always use a shorter tire to see what a gear change might do. Say a 26" tall tire compared to a 19" tire.