monkeyboy

i am in the process of getting my block machined to make a 392 all bore motor. i have GTP S2+(2.02/1.57) heads now, but i am really having a tough time deciding on what to do. should i just slap these heads on the motor swap the 918 springs for 921s and make up for the flow with a bigger cam? or should i send the heads back to GTP and upgrade to a S3(2.05/1.6) head? what really worries me is that the S2+ will not be enough head to get me into the 10.8 range n/a. lemme know what you guys think.

Jimmy98Z

I would go with some stage 3 LS6 heads they work really well with big bore motors.
Jimmy

99 Black Bird T/A

iTrader: (4)

All Bore I would go with the 2.05 or 2.08's on intake to take max advantage of that Bigger Bore.

What size Bore 4.125?

Wet or Dry block?

It run good with the 2.02's but you'll be giving up a little bit.

monkeyboy

i have 5.3L heads now.

ArcticFormula

Cool goals,
but what are your goals for this car?
Nitrous is out of the question or forced induction?
Regards,

99 Black Bird T/A

iTrader: (4)

If you consider other heads like the LS6's I would really check out TEA's new 2.5 LS6 up to 330 cfm rocks!

monkeyboy

the car will have NX direct port with a 250 shot max; i wanna hit at least 10.8 n/a and 9.9 on the dope. i cant afford to get new LS6 heads, i already am spending bucks on the machining(4.1 bore), cam, and so on.

99 Black Bird T/A

iTrader: (4)

I know if your going to spray that big a shot I would go with TEA.

TEA has a special NOS exhaust port for exactly that sort of thing.

99 Black Bird T/A

iTrader: (4)

BTW - which cam are you thinking about for this application?

monkeyboy

cam...238/244 .600+ lift. but i know for a fact that TEA heads will not outflow the GTP S3 that i wanna get and GTP has some cool options for the exhaust side for my sprayin' pleasure. but this post is not about which heads are better, just wanna know which option to go with.

DONAIMIAN

iTrader: (18)

If your able to, by all means get them. You will be leaving some on the table, but how much would these heads that you want to get cost.

monkeyboy

to send these (GTP S2+) that i have now to get upgraded to S3 will be 1000+ depending on the options i get.

99 Black Bird T/A

iTrader: (4)

That's a hell of a cam for sure...what LSA? XE-R or solid roller?

Unless you have had flow testing done on an independent bench with the GTP's vs new Judson Sig 2.5's TEA's you really can't much of a claim about know which flow what. If you do have the data from flow testing the GTP's against the new TEA 2.5's please post the data and share with the rest of the board.

Why so touchy about the GTP's, just putting stuff out there for you to consider...isn't that why you posted the thread?

In any case the bigger valves will help but $1000+ for slightly bigger valves is a lot of money. How much will it cost to just open the chamber up for the 4.1 bore and keep the current valves.

BTW - If you sell the GTP's for say $1300 and add another ~$700 or so for upgrade you could get a set of Patriot LS6 style heads set up with 2.08 valves for your application. If people still think the GTP's are the hot ticket today you'll probably get more than $1300 for them.

The Patriot LS6 was designed with bigger guides and stuff so you can upgrade to 2.08's without redoing the guides etc. Port work was also designed to flow best with 2.08 valve.

Stage 3
Chamber(LQ9) 71.06 .100 .200 .300 ...400 ..500 .550 .600
Int_cc 225................. 78...147...209...255...296... 312...322
Exh_cc 83 ..................66...124..164... 206... 229...232.. 237

Note that's on a 4.0 bore and they should pick more on a 4.1 bore. Would be nice to see what they do compare directly against the GTP's on the same bench

monkeyboy

i am sorry, i didnt wanna come off sounding rude. TEA just hasnt posted the times or numbers for me to be impressed with, muchless PP. i wanna stick to GTP.

its on a hydraulic cam 114(maybe). i did think about what you mentioned, but i forgot to ask craig about the cost to just open up the chamber to accomidate the 4.1 bore.

which route (from the 2 i mentioned )would you go with black bird

99 Black Bird T/A

iTrader: (4)

No problem - sorry if I started sound like a wasn't my intent.

Well let me ask one more quesiton...are you getting an LSX intake for the engine?

I would spend the $$$$ that over going from 2.02's to 2.08's probably.

I'd probably open the chamber up, get the LSX intake and keep the 2.02's.

monkeyboy

have not thought about the LSX intake. but that is an interesting idea. this is the cars specs so far:

resleeved 4.1 bore 3.7ish stroke
238/244 .600+ lift cam
GTP stage?
1 7/8 TR headers
12 bolt- 3.73 gears
LS6 intake

i just wanna hit at least 10.8 n/a....

monkeyboy

anyone have any advice??

2000RATA

If your GTP's were putting out some good numbers there is no reason they wouldn't do it on a larger CID motor. It would simply make more power. BTW I have before and after flow sheets on GTP 5.3's with 2.02's and 2.055's after if your interested.

Chris

Nytmare

Blackbird, those Patriot #'s look ok, but too me they look like a hogged out ls6 head ! Where are the low/mid range flow #'s ? Peak cfm means nothing if it isn't backed up by low and mid range !!!! I guess you get what you pay for ! My Absolute Speed heads WILL make an Azz out of those ( Without the Updates ) ! Monkeyboy, send those GTp's off and get their updates ! If You sell them , then you might be the STUPIDEST person ever too lace up a pair of boots !

99 Black Bird T/A

iTrader: (4)

Nytmare - Chill, I know about peak numbers and what they mean...I was just posting some data for Monkeyboy to take a look at because of the valve size discussion.

Nytmare how about posting up some hard data like a dyno sheet that shows your Absolutes vs thoes Pat's on the same car or two identical cars with the same mods and one with Absolutes and the other with Pats. I would like to see the hard data...MPH in the 1/4 on the similar cars with same weight and other mods would be worth looking at too...it's best to back up your claims with hard data otherwise...well we all know about opinions...

BTW - like TEA, MTI, Futral, Raging, Absolute, GTP, Patriot, Cartek, LGM, and a few others for head work because they do a quality product and provide good customer service. Open discussion means putting brand loyalty on the shelf.