Top end component selection

[90K1/2ton]

Thanks for your input. Would I be better off running a single pattern cam? I've read that they tend to produce more mid-low end torque.
Also, I came across Promaxx performance Vortec cylinder heads.

They have 64cc combustion chambers, 2.02" intake/1.60" exhaust valves and a larger, 185cc intake runner. The exhaust runner is 60cc. Max valve lift is .575" which would still allow me to safely run the LT4 hot cam kit. The can be purchased from summit for $764/pair. For comparison, the RA2 heads from SDPC are $874/pair.


Thanks

 

[Rusty Nail]

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[Rusty Nail]

IMO the Promaxx Vortecs are hands down the BEST bang- for-the- buck heads on the market today.

I dont have personal experience necessary to speculate on cam profile for you but i can offer this;
My SS runs the Promaxx heads i linked, an old-school ERSON AH-8 extreme flow cam, (.492/.492) and Street Avenger 770 on a Weiand 7546 in a 2700 lb. street/strip car with 3.73s that HOOKS. HONESTLY it pulls HAAAARRRDDD in the top end and is tuned to run a quarter as fast is possible. Single plane / single pattern. The low/mid you speak of and are after is NOT THERE but after about 70 m.p.h. you can forget catching me. My feet per second is TOO GREAT.
The reason i mentioned no weight/tire fryer is because that pushes your operating range much higher than you anticipate... leaf springs...axle wrap...tire hop...gonna push your rpms up - where the REAL power is found in MY combo and i have experience in that.
Like building for low rpm power in a mud truck, why? TOO MUCH tire spin!

Future plans include a Holley 300-25 and 4.56. That should push me to 12.5@100 in the 1320 and i could drive it to work but that's not what you're after.

 

[90K1/2ton]

They seemed like a no brainier. I know you recommended a single plane but I'm really wanting to make a boat load of torque early in the power band.I've read good things about edelbrocks rpm air gap dual plane intakes for Vortec heads. Supposed to be 1500-1500 rpm. Your thoughts, anyone?

 

[90K1/2ton]

More than one person here suggested that I keep fuel injection. Would it be possible to tune this combination with dynamic efi's EBL tuner, a bored tbi unit/intake manifold and fuel pressure regulator? Also, would retaining fuel injection hinder the engine's performance potential vs a 4bbl carb/intake?

 

[Supercharged111]

You can run a carb intake, TBI adapter, and bored out TBI and I'm not seeing where you'd lose performance. I also don't see why EBL wouldn't work, they tolerate boost and all. You could also go the chip route and do a real EFI setup.

 

[90K1/2ton]

What do you mean when you say "the chip route and do a real EFI setup?"

 

[Supercharged111]

ECM swap, I wanna say it's called the 7747 or something like that. It'll control something with 8 injectors.

 

[90K1/2ton]

I see. I'll be honest, that's way beyond both my mechanical and mental ability. I've been leaning towards carburetion because it's simple and many people know how to tune them. I was inquiring about TBI because the truck came with it and learning to tune it sounded interesting.

 

[Supercharged111]

Many people think they know how to tune carbs. Changing jets until it doesn't stumble or smoke is not tuning a carb. Without a dyno, the only good way is to use a wideband which NOBODY does. Carbs are easy because most of the time you can bolt it on and go. I tuned my old Edelbrock 600 to 14.7 cruise/idle and 12.9 WOT. I had to dig deep to find the needles with that big of a transition too. My friend used a Holley and there was no way to change how big of a step there was between light/high load (aside from the secondary jets but for some reason even there we couldn't find a nice happy medium). The real deal killers for me with carbs is 4 seasons operation (which the Eddy did well, minus the vapor lock), the aforementioned lack of tuning flexibility, less torque (because of shorter runners) than EFI, and they require re-jetting for altitude changes. If multipoint scares you, then EBL tuning a bored TBI would be super easy and give you most of the benefit of EFI (minus long runner torque). You'd get a much better tune on it than with a carb with fewer compromises.