Installing a 533ci Big Block in a 70s Ford Bronco - Bodacious Big-Block Part 2

The L&L headers come in three varieties. Your choices are the full-length, fenderwell-exit model mentioned earlier (79750A), a full-length, chassis-exit set (79750G), and a new shorty header (79750H). We went with the shorties to keep maximum ground clearance. All are formed from 14-gauge tubing, have oversized port openings, use 1/2-inch (yes, 1/2-inch) thick port flanges, and are all covered in a electroless nickel plating that allows for a lifetime warranty against rust. Heavy-duty!

It's all the little details that can cause the greatest grief in life and engine swaps. Thanks to the cool kits from L&L Products, most of the grief is turned into relief, but there are a few pieces you'll still need to scrounge. If you started your project with a salvage-yard big-block most of these will come from the donor, but if your engine came from a shop, you'll need to lay your hands on a few things. The flywheel shield (or motor plate) from the 351M/400 (arrow) will need to be replaced with one from a big-block (D1AZ-7007-A) since the egg-shaped crankshaft hole won't fit over the 460's crank flange.

Two of the items you can use from your old 351M/400 are the distributor and the starter, but why go cheapskate on these last goodies? Get an aftermarket distributor of your choice to provide a nice, fat ignition spark, and a good gear-reduction starter. We used Powermaster's XS Torque starter (9505) for light weight and tons of cranking power.

You'll also have to get a new fan clutch. As mentioned earlier, the pilot bore is 5/8 inch for the 460 (right) and it's too risky to ream out the 351M/400's 1/2-inch bore to fit. A spinning fan shearing off a running engine will take out an amazing amount of underhood items and ruin your day. And what if the hood happens to be open with someone standing in line? Bad mojo, baby, yeah. The original fan will bolt right up to the new clutch.

A few more widgets you'll need to think about are a coil bracket, vacuum fittings, and sending units. We used the sturdy stock 460 bracket for our coil.

We also used a factory vacuum tree for the many vacuum lines that are on this vintage of Ford. You can use the sending units (oil and water temperature) from your 351M/400. Just be sure they are the correct match for what your dash holds--gauges or lights.

To top everything off we used the last piece of our Edelbrock Power Package, a Performer Series carburetor. Edelbrock recommends the EPS 800 (as in cfm) carb with electric choke (1413) and it fit with no problems. We also added its spring-loaded needles and seats (1465) to help off-road performance.
We used a fuel pressure gauge from XRP (Xtreme Racing Products) and a whole bunch of their AN fittings and tubing from Inline Tube to plumb everything. If you're still using the hardware-store, 45-degree brass stuff, give XRP a call next time and try its anodized aluminum 37-degree fittings. They make a world of difference since they're easy to work with, leak-free, and lightweight.

Finally, purchase a pre-luber from ARP and use it before firing that engine the first time. Use your drill motor on one end and engage the other end into the distributor drive at the oil pump. Spin the drill and wait for oil pressure to show on a gauge. This will eliminate a dry start when you're ready to fire the engine and prevent premature damage to all those new components.

Put the piston in the number-one cylinder at top-dead-center on the compression stroke and then back off the crank to about 10 degrees before-top-dead-center. Install the distributor with the rotor facing the number-one plug terminal and you're ready to fire it up. Remember to run your new engine for a minimum of 20 minutes at 2,000 rpm to properly break in the camshaft and valvetrain. Now you're ready to enjoy a truckload of torque, but watch that right foot!