Sport Side

iTrader: (6)

That cam was matched to the AFR 225 flow numbers correct?

Scream

iTrader: (6)

Well, I sent in two requests, one for a 383 w/ stock LS1 heads, and one w/ AFR 225's. The cam they recommended was the same, but they said:

"SAME CAM WITH PORTED HEADS WILL MAKE POWER HIGHER THAN STOCK HEADS."

I didn't really understand that, but figure they know what they are talking about.

Sport Side

iTrader: (6)

Think about it this way. With an efficient head. You can hold the valves open for a lesser amount of time to make the same power.

The head is doing all of the work. With a stock head that flows 230cfm app., a large camshaft is needed. The large camshafts holds the valves open longer and you get the equivalent of a free flowing head.

Big camshafts are needed for inefficient heads.
Small camshafts are used with efficient heads.

Lost?

That quote is saying. A huge camshaft (allows a bunch of air in) and an efficient head (allowing even more air in), would make a ton of top end power.

Scream

iTrader: (6)

But what's wrong w/ going w/ a larger cam to get BETTER numbers with better flowing heads?

Sport Side

iTrader: (6)

Depends on what you consider 'better'. Average power, or peak numbers.

Like I said, a huge camshaft and an efficient head will make all top end power.

Scream

iTrader: (6)

I'm going w/ the 80-e and either 3.73s or 4.10s w/ a 3200-stall Yank converter. I don't want a "peaky" cam...I want something that delivers good torque but still pulls nice and hard up top.

So adding heads will just raise my peak power? Now I'm confused...

Sport Side

iTrader: (6)

Higher flowing heads can use a smaller camshaft to make the same rpm peak as a shitty flowing head and a huge camshaft.

Example.

LS1.
Comp 220 x-er on a 110 +0
6200rpm peak.

LS1.
Comp 210 110 + 0
AFR heads.
6200rpm peak.

greentahoe

iTrader: (2)

I think he means that going with a larger cam in conjunction with heads as opposed to the smaller cam with same heads would make the power come in later in the powerband. Smaller cam will peak sooner and allow more usable torque and HP.... I think

Scream

iTrader: (6)

If not the 233/239, then what would you recommend?

Sport Side

iTrader: (6)

I'm a fan of customs. Especially with unordinary setups. 383 w/ 225cc heads.

I'm not trying to talk you out of a camshaft that size, but it is important to remember some of those details, otherwise you'll compromise low end power....Which will more than likely be highly needed in a 4500lb truck.

I'd use the c-motion custom, before the TSP grind, mainly because .05 doesn't tell much. Have a c-motion grind spec'd to your setup once you get every detail of the setup in order.

This guy I talk to has a cam-motion custom paired with a set of ported cylinder heads. Your typical fast ramped camshaft will have 140* of duration or more @ .200 with the stock heads.

Because his heads are so efficient, only 132* of duration was used @ .2''. The TSP may do the job, but fitting the correct cam in for your setup will possibly do better. Personally, I don't feel the tsp 233 was designed around a 4500lb truck with a 383 & afr heads, and 4l80-e tranny. And all of those parts do indeed matter.

I myself wouldn't use cam-motion. I follow another cam-design approach. Follow is the key word there