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Discussion Starter · #1 ·
I installed a new set of edelbrock heads and an edelbrock performer rpm 460 intake.
This is on my 78 bronco.

I am running stock exhaust manifolds for the 460 with a d3 cast number.

What size bolts are needed to attach them to the heads? Google has given conflicting measurements. I bought some 3/8x 16 by 1 1/4" bolts. They appear to be too short. Especially on the 1, 5 , 2 ,6 cylinders. Where I believe there were studs for the heat shield.
I have searched for an exhaust bolt kit online. But they don't list sizes of the bolts, and have an odd number of bolts in the kit (11 bolts?)

What size do I need to buy? I am not running heat shields, so I should not need studs, but will need longer bolts.


I also installed a new intake. I was unable to pull all of the old vacuum fittings off. As well as the water port that goes to the heater core.

How many vacuum ports do I actually need to run?
I was able to salvage the brake booster fitting, as well as a single port barbed fitting.
The engine only appears to have a need for the vacuum advance. Which was plumbed off the carb.
I am tempted to just plug the holes and get her running.

What size fittings does the intake use? The port for the heater is larger than the vacuum.


Thanks in advance.
 

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1979 Bronco Ranger XLT, 400m engine, C6 trans, D44 front with Dick Cepek manual hubs
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I can only help with Vacuum, my 79 400 engine has no smog any more, no A/C, the only vacuum connections I have:
intake manifold to gearbox (C6 auto)
carb rear to brake booster
carb side port to vacuum advance on distributor

anything else is off. I am not even sure if I need a vacuum reservoir, for now its working as described or at least was until the engine did not want to start/run anymore.
 

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1979 Bronco Ranger XLT, 400m engine, C6 trans, D44 front with Dick Cepek manual hubs
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1,181 Posts
in terms of bolts, listed @ speedway motors, there is this for the 460

so basically exactly what you got
 

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Discussion Starter · #4 ·
I ended up using 3/8"x16 by 1 1/4" for the exhaust manifolds. Then using 1 1/2" for the holes where the studs were. I had around 1/2" of thread engagement.

If I went any longer on the bolt sizes, they would bottom out and not get tight.
I think the 3/4" bolts are for headers that have thinner flanges.

For the vacuum ports, it ended up being 1/2" not for the water port. And 3/8" not for all the others.

I had it almost buttoned up last night, but the hose clamp to the fuel line to the carb had been smashed and I did not want to risk it catching fire.
 
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