IIRC that 420hp figure came about from an engine dynoed with no accessories. If that figure were true it would equate to about 370rwhp in a M6 and about what you posted for an auto. It would be good for very low 12's to high 11's.

 

Hope not off topic or hijacking by any means, but I just got 96 z28 2 weeks ago. This car runs too strong and sounds mean as hell to be stock. But my point is there is no way for me to know what was done to the car. I am not gonna tare it down for the hell of it to see.
I have to really consider, when the time comes I am rdy, to think on cams/heads. Soo much to consider!

 

Sure there is. Go to the track.

 

How would going to track tell me anything. New car to me.

 

if you get times, we can tell you if it is modified

 

Compare your times with what most people have gotten out of a stock LT1. It won't be exact, but if you're running more than a second quicker than most stock LT1's you'll know your car isn't stock. If it's within a couple tenths, well that can vary with weather.

 

Ok. Good points. Could also be driver error as well. All my runs have been with autos. 1st man for me.

 

Thanks by the way.

 

This makes my head hurt.

 

Huh? I am lost

 

Don't worry about it. Take the car to the track and see what kind of results you get. If you've never been it will take practice to become consistent especially on street tires. What everyone is looking for is what kind of MPH you run. MPH through the traps is a good indicator of what kind of horsepower you are putting down. Most bone stock Camaro f-bodys run between 95 to 100mph given the kind of track conditions you are up against like track elevation, temperature, humidity... (density altitude to make it simple). Just go to the track and report your results. You will have fun guaranteed. BTW, where do you live? Some here may have been to a track close to you and can give you good info.
Do explain.

 

SS I live in Vegas. Been to the track, but on my VRod.

 

Yeesh. Lots of altitude at heat.

 

Who's heads? Mine?

 

Lol. That's funny.

 

You have to realize what edelbrock is. They make "new" products for many different types of motors. They are one of the few that still support aftermarket lt1 products. I'm not saying everything they make is top notch, but they do make some good products. Would I buy a lt1 specific product from them, probably not. I do run a 4500 flange intake from them.

Bottom line is like a stock crank, the lt1 heads are able to be reused on rebuilds.

 

I didn't read the whole thing but let's break it down to simple facts, the LT1 Edelbrock kit makes less flywheel power according to the marketing department than most guys expect at the tires from ported GM stuff. Does there need to be any further discussion?

Car Craft or someone did a Edelbrock heads/cam build on a Caprice with nitrous that ran roughly what my old 190cc heads/cam setup ran on frigging street tires NA.
Granted we don't have a lot of data on the stuff, but the data we do have paints a very clear and underperforming picture.

Edelbrock only released LT1/LT4 intakes after GM stopped making the LT4 intake. In the 90s they admitted failure which took integrity. Few yeas later when there is renewed interest due to the buzz around the cancelation of the GM LT4 intake they jumped in and put a NOT AN UPGRADE intake on vendor shelves.

Then again the LT4 intake as cast is not an upgrade over the LT1 either, it even has smaller ports than the early rectangular port LT1 intakes.
MANY MANY folks could not be bothered with research or understanding though.

 

With that said, it would certainly appear to me that there are options for people that are far better from a HP/$$$ standpoint than what Edelbrock offers for the GEN 2 engines. However, a lot of that discussion seems centered around running ported stock castings from a few different outfits.

The OP asked a question, based on his setup, which probably much tamer than the average Head and Cam (much less stroker and power adder setups) 350/355, if the Edelbrock heads would be worthwhile. This is given his constraints of a 2.73 rear, fuel mileage concerns, and the need for a bolt and go head.

I am not about to dispute the value of being able to either have a shop one trusts blueprint/check out/re-re/whatever a new set of assembled heads, assemble your own heads, or have the time to have Elliot Portworks do their thing.

What I am going to state is that there are those out there that need an off the shelf solution. I am an engineer with a background that includes Tier 1 Automotive powertrain filtration. I get cleanliness very well.

I also do not have the skill, setup, or tools...nor the budget to add money to have someone custom set up or blueprint a set of heads.

And I live where the driving season is short...if I lose a head to a spring or seal failure (anything that does not require a total engine teardown), I pretty much can guarantee that I really don't have 3 weeks to wait for a set of heads from anyone because that issue will creep up probably in mid July or early August. I would need a head that I can call and get from a shop in the time it takes them to ship it via UPS/FedEx.

I hate to rant, but it seems that the OP's context and situation were lost here. The guy has a relatively mild combination and needs a head that he can bolt on and go that will give him a boost of 15-25hp over stock. Would that head be Trick Flow, AFR (which seems to build to order), Edelbrock, Dart, or a place like Golen that might have something sitting on the shelf?

If Golen has ported LT1 heads...their site is a little vague on this...in stock, I'd probably go that route and stick a cam one or maybe two steps up like LE's 212/222 or 218/224 cams and go from there.

Does that make sense?

The guy isn't looking for 400+fwhp with a reasonably priced, quality off the shelf head, he's looking for 300-325 fwhp. If Edelbrock isn't the best solution on that, who is?

My $0.25

-Dave

 

Don't bring Golen into this thread.

 

LPE. Their CNC ported LT1/4 castings, ported intake and 211/219 cam will easily yield 420 flywheel hp (As long as it's put together properly), have all the street manners of stock and get as good or better gas mileage as stock all for about the same price, or maybe better if you were to compare Edelbrock's heads/intake and whatever cam chosen.