So, I am buying a car with a LQ4, afr 205 heads, bbk 85mm intake, bbk 1 3/4 LT headers with matching 2.5" ORY and comp 224 cam with XER lobes. Would going to 1 3/4 stepped headers or 1 7/8 be worth the price for the gain, generally see a 10 hp increase.

 

Sorry, on my phone, but I am also going to go with a mamo ported fast 102 and maybe even have him work over my heads. So thought ide ad that to the potential power figure of going with larger primaries.

This is going to be my street car, almost DD so its not going to be seeing top end power frequently so would like to retain low and mid range power.

 

IMO, yes it'll be worth the cost, but not if you bottleneck it down to a 3" exit on the Y-pipe merger; you'll want a 4" exit on the Y-pipe merger.
I think the stepped headers would give more HP/TQ where you want it.

 

i was considering going to bigger LTs eventually so if youre looking for more power i think its worth it.

 

As it sits its dynoed, 448 whp and 419 wtq. After talking with mamo, he estimated at least 15 hp increase over base 102 and 15 hp increase with the heads worked over. I know this beast is quite capable of 500 whp and be streetable, so looking for a path.

 

If your going to some Mamofied 205s, and a 102, I think youll definitly want to run a 1 7/8" header, and a real Y pipe. I think the smaller headers, and 2.5" Y are holding you back even on your current setup.

I think, if its in your budget, you should have Tony spec you a cam to REALLY bring up the power!

 

I was thinking about it but won't know till the end of the year which will give me enough time to mull this over. I am already looking at 2g's to have my 205 mamofied along with a 102. Plus another 700 for tsp 1 7/8 headers and ORY. At the end of april I am dropping 1200 on a fbody 12 bolt, coming out of a lt1 camaro. It would be awesome but gotta see if the wife will let me

 

Consider getting the 12bolt anyway in April, you 10 bolt like mine is probably running on borrowed time.

 

ya, i am deffinately getting the 12 bolt and have started making arrangements for it. if i could make 500 whp on a 12bolt ide be very happy. everything else mentioned above (mamofied heads and fast, and custom spec'd cam) with the exception of the headers and y, those arnt too expensive from tsp, are going to have to wait till the end of the year. i could prolly throw the heads and intake on without driveability problems, but i will have to drive to phoenix when the time comes to have my cam installed, larger inj, and 85mm maf with dyno tune.

 

Check out the thread in the dyno section (I believe) that shows an apples-to-apples comparison of swapping 1.75" to 1.875" primary headers, FAST 102, etc. There is definitely upside with the swap, however I was absolutely floored at the low and midrange torque figures (in a really, really good way).