Ernie W

iTrader: (1)

I've decided to build an engine for my T/A. I plan on going with the BTR weisco 4.070" pistons on stock L92 rods and a stock 24x crank in a iron LQ4 block.

I have two sets of heads, both of which need work done.

First is a set of 243 heads from a 5.3, they have some guide play and I had planned on having them milled so why not send them to Advanced Inductions for the 232cc port work along with the 2.05" intake valve. The only downfall is I only have a LS6 intake manifold for now until I could pony up for a FAST 102.

Second I have a pair of 5364 L92 heads. They need some work also, guides have some wear. I have new gm LS3 hollow stem valves for them also. These I would probably just have valve job, possibly milled and install them. No port work on these. I also have a stock LS3 intake manifold setup.

I would have a cam spec'd for either setup as the Vengeance Racing VRX5 cam I have probably wouldn't be best for it. I'm just curious as to which would have more power potential. May also consider spraying a small shot later on.

Lets hear some opinions...
Thanks,
Eric

ragtopz28

iTrader: (57)

This is a huge debate (cathedral vs. rectangular, search and you will see).
IMHO and what I did (on a stock LQ4 bore)....ported/milled L92's and a LS3 intake for top end hp.. Others will say the 243's for better low/drivability. From what I am told, the bigger the bore the more the rectangular shine.
Let the hate begin....

Ernie W

iTrader: (1)

I know it, a local guy I know has a C6 Z06 procharged and swapped to TFS245's and gained around 200rwhp IIRC. Its the quickest 6 speed Z06, ran like a 8.77 1/4.

My car is currently a stock LQ4 with LS6 intake manifold. I have another block and all the parts, just don't know which direction I should take.

HCI2000SS

iTrader: (2)

Honestly I'd go with whichever is the better deal

Darth_V8r

iTrader: (4)

With that 4.070" bore, I think the L92 is a great option. I do think that if you're wanting to keep that vrx5 cam, it will be better suited to a cathedral. If you plan to spray, I would go with porting and make sure the exhaust side is opened up as much as possible

kinglt-1

iTrader: (26)

Cathedrals

DietCoke

iTrader: (18)

The AI heads will make more power, everywhere.

SCott5

iTrader: (40)

Pretty sure you are talking about Jareds car which is boosted and I don't think it was that much, but he was able to make more power at less boost compared to his Trickflow 260s I think he had on it.

id say stick to cathedral.

Tuskyz28

Man that's a tough choice!! With either head the right cam can put a smile on your face. Otherwise on the c6z.... That's a whole totally different ball game comparing a LS7 head to a TFS 245 cathedral head...

Rise of the Phoenix

iTrader: (27)

My vote is for the AI ported 232cc heads. AI ported heads put down the power.

mOtOrHeAd MiKe

iTrader: (8)

Do the AIs; and tune the compression with pistons and valve events; milling for compression is a Band-aid.

ss454327

iTrader: (10)

I vote AI 243s as well. That Vengeance Racing VRX5 will still be a solid cam and you can change intake/cam down the road.

redtan

iTrader: (5)

Depends on where you want the power. I think the L92s will make more power up top especially if you only have an LS6 intake for the 243s. If it was a FAST102 that will change.

Although the smaller runner 243s will make better torque across the band and earlier, so I vote for those especially with a FAST intake.

Ernie W

iTrader: (1)

Yep, Jared's car. I was thinking it made 1050 on a dynojet on the ls7s and made around 1250 on James Shorts dyno with reading like a dynojet. Either way it made a nice power difference. But boost is way different than a N/A setup.

Tuskyz28

James Short dyno is stingy!! Very stingy.. my buddie 403ci T/A only put down like 45X to the tire but the car run 10s on motor with a M6

Ernie W

iTrader: (1)

Yea his dyno dynamics reads low compared to others. I was to say Jared's Z06 made like 927rwhp on it and 1050 on a dynojet.

Dave_62

iTrader: (10)

I can give you some real-world results for the AI 232cc heads. I've got a pair on a stock bottom end 346 with a 236/242 cam, 11:1 comp, and a FAST 92 intake/92mm throttle body. In a 3500lb G-body, through a 4L80E and a 9 inch rear the car traps 120MPH in the heat of summer. Sharp throttle response low/midrange, and power carries well upstairs too. I shift it at 7k.

Phil is a good guy to deal with, and his workmanship & attention to detail is top shelf.

DavidBoren

I would absolutely go with the 232cc Advanced Induction 243's, the VRX5 cam, and the LS6 intake. You can always get a custom cam spec'ed later when you get a FAST 102 intake.

What sort of exhaust are you running?

Ernie W

iTrader: (1)

My car currently has Speed Engineering 1-7/8" headers with 3" collectors, 3" x pipe with true duals and spintech super pro street mufflers. Its a pretty loud combo. I will soon be running it on out the back with dual 4" tips mounted directly on the muffler similar to a GTO or so.

Jtm2085

iTrader: (1)

Did you fly cut? Were they milled any?