300 6CYL

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Sep 19, 2012 | 04:11 PM

DOC G

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300 6CYL

I need to replace my 1981 F100 300 6 and have a 1985 300 long block available to me. Will this engine work. Thanx for any help.

Sep 19, 2012 | 04:29 PM

Labhound

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Yes it will.

Sep 19, 2012 | 07:17 PM

1983F1503004x4

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Make sure you keep the ignition components from the 81, as the 85 is a computer controlled model with a feedback carburetor. The 81 is a Duraspark II electronic ignition without the computer controlled carb.

Also, make sure you use the 81's carburetor and distributor.

Sep 19, 2012 | 08:05 PM

DOC G

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Thanx old motor has a holley 4bbl on an offy and headers. no
No emission. I will just move everything over to new block.

Sep 19, 2012 | 09:33 PM

1983F1503004x4

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Quote:

Originally Posted by DOC G

Thanx old motor has a holley 4bbl on an offy and headers. no
No emission. I will just move everything over to new block.

Are you running a fabbed up water-heating plate to bolt to the bottom of the intake?

The intake needs heat so the fuel doesn't puddle and cause bogging/inconsistent burning.

You'll notice better power, smoother running, and better gas mileage if you're running the plate. You also can't completely tune out the bogging from running the intake without heat.