Dual 3" exhaust with a decent muffler. 460's really need to breathe to get anything more that standard out of them. so I went from single 3" to dual when I put the new engine in. A good improvement, but the cherry bombs I had on it were poppy & noisy on downshifting after a few months of getting burnt in. And I was still tinkering with timing and carb adjustments trying to find the sweet spot. I finally got tired of the noise when the hotrod sound got old, and put on a dual in/out muffler. Not Flowmaster, and I'd have to go thru my emails to find the brand, but it was the cherry on the cake. Just enough back pressure to keep some power in the cylinders that I was looking for, and it took away that baffly pop.
Hmmmmm...... probably the Motorcraft intermittent wiper switch I just ordered to replace the non-Motorcraft switch I installed a couple of years ago....... (I cheaped out, against my better judgement) that just crapped out......
My 1978 Bronco Custom was probably 95% stock when I purchased it, unfortunately it developed a head gasket leak soon afterwards. I rebuilt the whole engine, a 400, at 103,000 miles. Being a gearhead at heart, I had to make some improvements. Compression was increases with pistons from TMeyer, a small hydraulic roller cam from Howards, oiling system modifications, mildly ported heads with Ferrea valves, Edelbrock Performer 400 intake a Holley 670 Street Avenger carburetor and MSD ignition. I've literally doubled the horsepower (not difficult to do!).
That's been my only real expenditure to this point and it has been well worth it. The 78-79 Broncos have always seemed like vehicles that should have MORE POWER, and I haven't been disappointed with the properly built 400.
A 4" lift is next, and it will be interesting to see if a good suspension can unseat the engine as "best mod"!