Would I benifit from a 4 and 7 firing order swap cam? What would be the difference between a normal cam and this swapped one?


my specs

454 2 bolt block 60 over
3.76 forged crank (aftermarket)
6.385” rods Scat H beam with ARP 2000 bolts
Wisco pistons:
1.520" Compression Height/+48.4cc/+.700" Dome Rise
Compression about 12.21:1
Copper head gasket .040
Victor Jr intake
Dart iron eagle heads (308) 119cc int 2.25 ex 1.88
28” tall tire
th400 trans

The major difference you'll notice is that it's a lot harder to remember the firing order.

The difference is very small but I did it anyways. Also popular is the 4/7 2/3 swap I believe and then you will have to tatoo the firing order on your hand.

less weight in your pocket, therefor allowing quicker et's

Didn't one of the magazines do a test comparing a regular cam and the 4/7 one? If I remember correctly the gain was negligible if any at all.

I don't think it would be worth the trouble.

What about the LS1 firing order?

I think I read that it gives a smoother idle.

what's the order with that swap? 18736542?

My understanding is that the 4/7 and 2/3 swaps give you a few hp (single digits) at high rpm (>7500). But, I've never tried this back to back on the dyno.

If you look at a typical dual-plane intake manifold, it won't take very long to figure out why the firing order is what it is, out of the limited possibilities.

And of course, there are only certain possible choices for the firing order, regardless; one look at a crankshaft provides a clue as to why.

If you have a single-plane intake, you MAY benefit; but the difference may be anywhere from a slight loss, to no detectable change, to a slight gain. The only way to know, is to try it on YOUR COMBO and see. If it's a gain at all, it will be SO SLIGHT, that it only has meaning in direct comparison to an otherwise identical motor with the same other parts around it.

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