Considering a winter engine upgrade
 

Considering an engine upgrade this winter. My goal is pretty simple, more power LOL. Nothing wrong with my current setup, I’d just like more as usual :D.
I’d like to get your opinion on the following upgrades. I think I have narrowed it down to two choices. One is fairly inexpensive and the other is a bit more.

Option #1:
Swap out my current ported 670 heads for a set of ported KRE d-ports (310-325cfm). I plan to buy them from KRE bare & ported and have Paul Carter put them together. Keep my current cam (Lunati Voodoo HR 239°/243° @ .050", ground on a 112° LSA), keep my current rockers, keep my Torker 2 intake and keep my RA manifolds.
At a minimum I would need to purchase the following: heads, ARP head bolts and gaskets.
This is by far the least expensive option. I have been told by some reputable Pontiac engine builder that this should net me around 560hp/600tq.

Option #2:
Swap out my current ported 670 heads for KRE High Ports, unported, North wind intake and change out the cam for a Lunati Voodoo HR 243/251 @ .050, ground on a 112 LSA.
At a minimum, this upgrade would require purchasing the following: Heads, intake, cam, push rods, roller rockers, head studs, headers and gaskets.
This is my most expensive option but I have been told that this would “easily” make 600hp / 600+tq. I have also been reading about the High Ports and found I will need to make or buy and different bracket for my AC compressor since those heads are missing a hole. Not real thrilled about this. I don’t want this upgrade snowball….

Curious what you guys think. If it was your money what would you do?
Would love to hear form those that went from ported iron heads to ported aluminum and their experience.

What you’re thinking of doing in option #1 looks like a decent plan.

However some headers would be the key to the additional power you’re seeking no matter which upgrade you decide to go with.

Yea that’s what I was thinking too. We did a back to back dyno test on my engine and the RA manifolds actually made more HP than headers. But I was thinking with the head upgrade having headers would only help.

My experience swapping from ported iron heads and a hft cam to a well setup ported aluminum head/ hyd roller cam package was literally a mind and a tire exploding experience.
Your first option is probably the best idea..but ditch the exhaust manifolds. The only thing i would change is possibly the cam? I don't know the exact specs of your cam..but to truly utilize the added flow of the new heads..you will want to have a high gross valve lift. In the .650 range or higher. The torker 2 will get the job done but it will need some plenum and runner work.

I think I would also go with option 1 but add headers and more cam to reach the power numbers you want.

The problem with option 2, other than what you mentioned already, is that while the Northwind is a good intake, it does not fit very well under a 67 hood unless you modify it by getting the carb flange angle milled etc. If you don't, the carb and air filter are angled up towards the front of the car and interfere with the hood unless you run a small air filter.

Two things are a fly in the ointment here!

First off running even stock KRE heads puts you right at the threshold air flow wise of what that T2 intake can flow, no less if the heads are reworked to flow upwards of 290 cfm!
I can’t think of a greater waste of money!

The next issue in regards to your first and second build choice is the exh manifolds your running.
Getting to the 600 hp level will be tuff without running the optional big size exh manifolds and a 3” exh system if your not there already, and forget right now about making good use of high port heads and topping the 600 hp mark by much while even running the big size exh manifolds, you will need headers!

I have spent a whole bunch of time heavily reworking a T2 intake( no welding But epoxy) and 285 cfm up from the stock 260 or so was it , and it needed a 1.5” spacer to really work right besides!

Where talking RA4 port size or better all the way to within 2” of the start of the transition to the plenum and then even more of a expansion rate kicking in and then that getting blended into a 2” spacer.

You did not post what your running for a carb, but with the high ports something more like a 950 is needed.

It is pushing it with the Torker 2 but it can support 600hp with some plenum and runner work and a one inch carb spacer.

Yup!
That’s why I mentioned compression needs to be factored in if keeping the ductile iron on the exh side.
You’ll need more cylinder pressure to drive the exh out!

Good stuff guys!
I forgot to mention that with running the Torker 2 intake I would pay Paul port match it to the heads.
If not the Torker 2, what intake would you recommend?

while a port match will help, if will not get you out of the woods and back to your cabin, at least in terms of running the high port heads.

If every runner in that intake was reworked to flow 275 cfm you would be at the 565 hp level assuming no restrictions on the exh side.
290 cfm would allow 75 hp per cylinder, or 596 hp.

How much power are you making now?

KRE just dyno'd a 461 with as cast heads, RPM and 60919 and it made 498 hp at 5000 rpm.

It took a sold 245 intake cfm to make that 498 hp and I likely would not be wrong by saying that it was tested thru headers also.

Mine made 520hp/580tq

SD ported iron heads?

Yessir

Option # 3, Instead of the High Port option run some of the new CNC chamber (same as High Port) Edelbrock heads with mild-medium port job.
First, your intake will not be raised up 3/4". Gives you more intake/spacer choices.
IMO the advantage High Ports have over good E heads is for a very narrow engine choice. More max effort deals.
Builds like you are planning E head wins. Some headaches are gone. You could run a Victor if you wanted with E heads. No need for KREs High Port crossover if you plan on running a thermostat. That is, if you want your cooling system to run like PMD intended.
I do not see any reason to raise your carb up for what you are doing.
BUT, you would have to wait for E heads to be back in stock.
This is what the bolt holes on the end of the head looks like if it will help your A/C bracket.

First one is 72cc head, 2nd is 87 cc head. Looks like they will be in stock November.

More tid bits to consider...

It is my understanding the as cast (no port work) High Port heads have about a 277cc intake runner volume. Also the High Port head uses a large 2.200" intake valve at a taller 2.000" installed height, thus a longer valve stem length at around 6.200". That is something to consider when evaluating the spring pressure to control the valvetrain mass involved.

Regarding the Torker II intake. Ken Crocie used one on a 535 cid combo that made 650 Hp. Nothing elaborate other than necessary TIG-welding above the ports, which needed to be machined flat and then port-matched to the tall cylinder head ports in use..


.

Interesting option 3. I like that. Where are you getting this info? Edelbrocks website?

Don’t the high ports have a issue with stock brake booster clearance?

Are you suggesting The new CNC chamber in round or D port?