Ok, so I'm 3yrs into riding out this combo. Still havent had it tuned but it runs just fine so I havent worried about it. I know currently I'm choking it with my crap stock intake. So I already plan on slappin a LS6 on there hopefully before the end of the year. I also got a buddy who is gonna tune my car I just gotta get him the cash for another liscense on his program.

What I'm really curious about is my heads/cam selection. Currently I'm running a set of stock cast 5.3 heads port/polished by Bo White milled .018" & with a 2.00" intake valve. Cam is a 224/224 .581/.581 114

I have a chance to grab a set of LS2 243 heads with fresh Patriot Gold duals for a steal of a price. But I'm on the fence. It's got me wondering if I'd pick up some power goin to the 243's and if so would I loose enough torque from swapping to those over the milled 5.3 heads to make me wish I had stayed with the 5.3's........

Let me hear your opinions, has anyone else with a smaller grind cam swapped from worked over/milled 5.3 heads to untouched 243's & if so what was your results & were you happy with the switch?

I was also pondering swappig out my 224 cam for a custom EPS cam similar to my 224 after seeing the results those have been getting.

If its not worth it I'll just throw some Katech rod bolts at it & fresh MLS head gaskets at the end of this year & call it a day.

 

In my opinion, I'd leave the heads alone and go with a custom grind from EPS a little bigger than a 224. If my car was an all motor car like yours, I probably wouldn't be happy with my 228r, but it loves the bottle. If I ever go all motor, my car will have a donkeydick big power cam in it, custom spec'd for what I need it to do.

 

Well I plan to hit it with a 100-150 shot & I know these 224 cams like the nitrous too. Plus I drive it 300+miles a week. Its my daily driver so I dont wanna get more cam than I'll really be happy with in traffic. I'd rather spray it when I need a edge & keep a smaller cam since I drive it so much.

I saw a thread where a guy laid down like 430/410 & 11.2 ET from EPS's 222 custom grind & stock 243 heads in a fresh LS6 short block at full weight. I'd be happy with some numbers like that & then be able to spray it if need be.

I really dont care too much about loping like a prostock car. Granted I do want to hear it some just for my own jollies, but it doesnt need to be extreme to make me happy.

 

So no one else has made the swap from worked 5.3's to 243's?

 

Your car will be a monster on the bottle. 150 or go home
I would stick with the 5.3s, seeing as they give you a bump in compression.

 

use the heads that flow the most.the worked 5.3 should flow better then the 243s if they are stock unmodified.do you know the flow numbers on your current heads?those numbers help in making a custom cam make more power.

 

If memory serves me correctly I believe this was the final numbers:

219 @ .600 lift on the exhaust side
261 @ .500 lift on the intake side (believe he said it stayed right at 261 all the way to .600 lift)

Bo did all the head work & Gunnar flowed them. I had Bo cut the valves for more low lift flow & slap a 2.00 intake valve in them instead of the stock 5.3 valves since most my racing ends up happening on the street randomly. He said I could swap out the intake valves for a 2.02 & bring up the top end flow.

 

260 is right at what a stock 243 head flows so unless they are ported just get a cam....

 

You know what, I completely overlook that. I just went into the sticky & found a print out of a flow sheet for stock LS6 heads. Looks like according to that sheet the stock LS6 heads flow:

183.2 @ .600 lift on the exhaust side
250.7 @ .500 lift on the intake side (only 257.2 @ .600)

So even though I'm not super flow/head savy, would I be safe to assume that my current heads actually out-perform a set of stock untouched 243's? I'm also betting it would be safe to say they are netting me more power being milled .018" as well. I know Bo told me these 5.3's are a 220cc runner as well.

I'm starting to think if I had a good tune & LS6 intake as I sit now I could be close to my 420-450rwhp range N/A.

Someone please correct me if I'm wrong here or if I'm missing important factors.

 

If you are going to get some work done on the 243's, I'd say go with those. They can always be milled down to equal the compression from the 5.3s, but as long as the port job is done by someone who knows what they are doing, they will outflow the 5.3s. If you are keeping the 243 stock, I'd say buy anyways and flip 'em for some cash.

As for the cam, those EPS lobes are working wonders for people, and claim to be very easy on the VT. something under/around 230s would be be ideal for you I imagine, without sacraficing street manners.

 

Yea, thats what I'm leaning towards now. I have talked with several others who didnt know my heads were flowing that good & they said the same thing. Just get the custom cam from Pat & call it a day. Hell I didnt even know they were flowing on par with stock 243's until I looked at the numbers. Previously I only compared them to other 5.3 heads, LOL.

And yea, those EPS lobes being easy on the VT is really catching my eye since I drive mine so many miles a year.