I'm getting ready to install Vengeance drop inn pistons and rods, Their stage 2 camshaft, 9.06 pulley, And Coardes racing 5" CAI. The mods I currently have are Magnuson 2300, 1 7/8 kooks with green cats, 95mm t.body, lt4 injectors and hpfp, 90mm pulley. I'm wondering what the gains would be with ported heads and if it would even be worth it without going to 2" headers? Who's recommended? Are any of the aftermarket heads good/better? I don't want to pull it apart but once( I hope)!!!!

 

This really depends on what your goals are and what you want to spend. For a boosted car, I would put my money on 2" headers first and foremost before I would worry about head options. However, stock castings are very capable and can flow very, very well. It'll all just depend on who you go through to do your head work and how well matched it is to your cam. For aftermarket options, I haven't seen anything that competes with the CID heads just yet. I haven't seen the Edelbrock/Katech heads in person but, I do know that they require custom headers to be made (typically sourced through Kooks). I haven't seen any real world data on the TSP LTx heads, either. The average I've seen is 25-35whp for ported stock heads (or much more depending on how far you want to go) but, your heads will be off the engine and frankly, I would take the time to address the heads while they're off now, to include the headers so you're not doubling up on labor costs.

Keep in mind that you have a boosted car and head flow characteristics will be something you need to have a good conversation with your tuner/engine builder on. There's a lot to be said about port velocity over port volume when you're looking at reaching very specific goals for specific applications (drag racing vs road racing).

 

When I was doing my research I found that nearly all CNC heads had the same flow number except Frankenstein heads they seemed to flow slightly better than others. Then you have hand ported heads, Pray claims some crazy numbers, I don't know if they flow those numbers but he charges crazy money to do it.

With that said, the casting on the LT heads are very inconsistent. I had to buy a replacement head because the previous porting job had made the walls too thin and it kept cracking. So I would consider a good show that will stand behind their work.

 

I checked with CID, TSP LTX heads, and also Katech. CID explained to me how the LT4 stock castings already have to much volume and make the air flow kind of lazy. Their ports are smaller, but flow better. Only reason I didn't go CID and went Frankenstein is because I was told I'd have to port my headers a little bit to match the exhaust port shape. I spoke with Frankenstein, LME, and TSP about head porting and found that Frankenstein was the best for me. I heard about LME porting to much in the past and heads cracking, but not really sure. My heads should be coming back in around 2 weeks from today.

 

Thanks for the info. Any reason why you didn't go with TSP LTX heads?

 

Edelbrock also offer aftermarket casting which is priced fair IMO

https://www.edelbrock.com/rpm-gen-v-...aft-77119.html

 

Just an FYI I believe those require their headers as it changes the angle.

 

You are probably referring to their Victor Jr Heads, which does require different headers. https://www.edelbrock.com/victor-jr-...aft-77139.html

However, Their RPM series heads have the exhaust ports at the stock location. Any LT exhaust manifold should fit

 

They require the same headers as katech and edlebrock which is the kooks. I already had purchased my 2" headers.

 

We've been using Frankenstein for about 3 years now and I can't say enough about their quality and customer service.

 

Frankenstein is awesome from customer service to the power gains.

 

Gm did a pretty good job on the Lt1 and you may see a little gain. My old Camaro Lt1 made over 850 rwhp with bone stock heads except for Valve springs. I'd stay with the 1 7/8 headers, thats what I had on my Camaro and my C7 Vette.

 

I'm hoping that you can forgive my ignorance here please, I can't take credit for having the same level of expertise on this topic as you. I have a Vortec SC on my 2014 Z51 A8 along with a 95mm ported TB and a Corsa Extreme exhaust, here in California everything has to meet CARB standards, only cat-back systems are street legal, the same for the blower. I'm adding a LPE GT35 cam kit, it's a baby cam I know, but again we have CARB standards. I'm considering having the stock heads ported and polished, not that I expect a huge boost, but it's my understanding that increasing air intake even some, along with a good tune can be worthwhile, even for someone like me who never tracks my car, your input is very welcomed,