still trying to figure a few things out on upgrades.
the car has a stock lower end LS1
im trying to figure out the best bang for my bucks since these 2 heads are really close in Flow numbers so im having a hard time trying to decide which one to go with...and honestly why go with one over the other.


plan for the car is a driver from time to time and Drag car. but will see more driving time than the track.
I do plan to do Cam which I am unsure on yet. that's next to figure out.
intake I plan to use a Fast 92 and Fast 92 TB.
also I plan to run a 150 shot max on the car also when at the track




Here are the 2 heads im trying to compare. can you all lend a little thought one which one would work better than the other and why. that would be a huge help.
PRC As-Cast 225cc LS1/LS2 Cathedral Heads..62cc...price $1799.99
this includes TSP .660 Dual spring kit with Titanium Retainers. hollow stem valves would be another $50...are the hollow stems worth the $50?
Flow Data (4.00" Flow Plate - No Exhaust Pipe):






PRC Stage 2.5 LS6 CNC Ported Heads...62cc....price $1649.99
also with the same TSP .660 Dual Spring kit and titanium retainers.
Flow Data: 3.910" Flow Plate - No Exhaust Pipe


Lift Intake Flow Exhaust Flow .200" 147 cfm 114 cfm .300" 209 cfm 152 cfm .400" 258 cfm 191 cfm .500" 294 cfm 207 cfm .600" 316 cfm 226 cfm any help or opinions would be a huge help in understanding one over the other and which would be best for my application.

 

sorry fellas...thought that would come out in the post better than that.


also something else that I also was concedering was trying to find a set of 243 heads and just having Texas speed do the stage 2.5 port job and add the TSP spring kit that would put that price at $1199.99

 

Finding a set of of 243's and having TSP do their work sounds like a better bang for the buck IMO

 

buddy of mine has a set he wants $300 for
so add that to the TSP work. now im up to $1499.99.


so there is a little bit of savings there

 

I'd also call ask TSP and ask their experience and opinions between the two heads. Forget the flow numbers... I'd wanna know real world differences

 

and they also go from 58-64 cc chambers also.
running nitrous I wouldn't think I would runt to go to high in compression either

 

If wanting to run pump gas I'd keep the compression no higher than 11.5 in general. Same would apply with smaller shots of nitrous

 

I'd go PRC as cast 225s.....and the Hollow valves for that valve train stability when on the NOS
Also the thicker deck surface would help head gasket sealing as your cylinder pressures will be skyrocketing on the NOS
They have the slightly altered valve angle to give near stock PTV clearance even though they're 2.06 diameter intakes
I would have to pull them apart and do some creative cartridge roll blending but that's just me....Get the powdered metal guides and plan for a stock rocker bushed trunion upgrade as well....TSP makes some nice cam grinds too....people over there are great to deal with

 

For only $150 difference I would for sure go with the Trick Flow. There is more benefits than just the flow as mentioned above. The main one I was going to mention was the valve angle. The thicker deck surface is a big plus too that AR shale mentioned.

If you use stock rockers on the Trick Flow heads you'll need to grind of the small tabs on the bottom of the rocker stand.

And like AR shale mentioned use stock trunions or go with bushing trunions. The aftermarket roller trunions are having wear issues.

 

The as-cast heads mentioned above are not TrickFlow, they are PRC, as made by Texas Speed and Performance.

 

Keep in mind that bow benches can be like dynos, also the data on the TSP's are on a smaller bore.

you could also keep an eye on the classifieds to save a bit, also consider the other major porting companies (AI, TEA...). I ended up scoring a set of fresh rebuilt AI 232cc heads with 62cc chambers, valves, springs, and retainers for $1200 shipped.

 

Not even a question in my opinion. Most certainly go with the aftermarket casting

 

On a 3.9 inch bore I've read that there isn't much gain with the larger valves of the Stage 2.5 vs the Stage 1 stock sized valves. That saves some money.

 

If you look at flow #'s of Stage I vs. Stage 2.5, you will see that there is very little difference between them. Like you said, I would think that on a 5.3 there would be even more shrouding with the larger valves, making the Stage I an obvious choice for many of the smaller bore engines.

 

The prc heads are gonna out perform the 243s. Is there a budget or a goal as far as e.t/mph? I have stage 2.5 243s and there badass but I would have loved to get the prc heads after doing the math.

 

So I have seen the Trick Flow and AFR heads come up in talking in a few threads.
which ones are you all talking about?

 

Trick Flow "as cast 220s" or the new Mamo Sportsman 223s are fantastic pieces

 

man now another one to consider

 

Another positive aspect of the 220 is the ability to put them on a bigger bore down the road to de-shroud the valve. A bigger valve in smaller bore still benefits because 80% of it nowhere near the cylinder.

 

Put a set of as cast 220's on a buddies car and they made me a believer. I highly recommend them.