Gen 6 big block.

[Supercharged111]

I put a 212/218 .520/.530 115+2 cam in mine and it idles like glass. I'm not sure what your concern is with the fuel injection.

 

[Christian Steffen]

Thank you for all the information. I've decided to order a 489 rotating assembly, i was just hoping to find a much cheaper route to go. I had seen a complete overhaul kit for an 8.1 for around $600 plus add the crank for another $300 and I would have been golden but obviuosly that won't work with the 8.1 being a tall deck with longer rods. @L29Sub, did that cam work well with the FI? And, what kind of mileage did you see after the build, was there any improvement over the stock 7.4?

I have the same cam as l29 sub in my 489 (~9.6:1 cr). No issues whatsoever with the FI or idling. Just make sure you keep usage in mind. For a 100% tow rig I'd probably go a little smaller, maybe in the something between 256 and 268 duration. Tighter lsa too.

That being said I have no complains about the xe270-13. Back when I was NA if I'd drive it nice I could get 14 mpg on the highway at 65-70 mph.

 

[Christian Steffen]

Looking at the same mods for my 97 K2500 L29, depending on the cost.

@L29Sub, same questions as Dinkster on the FI and also black box upgrades needed (BlackBear?) Did you have to clearance the block for the new crank/rods? If so, how much extra work was that? What did the crank kit cost? The cam LSA is 113, do you have an auto trans and need the vacuum, any thought of a 109 or 110 LSA, did Comp Cams spec the cam for you?

@Dinkster, please share your crank kit order details and cam you're going to run.

Has anyone done basic port cleanup/polishing on those vortec heads and see any gains from that? not looking to custom flow the heads, just smooth the rough edges out while they are getting worked on.

Planning on shorty headers. Has anyone closed off the ERG, deleted the cats and seen any problems or benefits? The tune mods can delete both of the erg and behind the cat sensors, so can save a little bit of time/cost with the new exhaust setup.

No clearance work necessary as far as I remember. Definitely get a tune, custom is best but black bear does good work from what I hear.

Trans doesn't use vacuum for anything?.. brakes might but it seems like most 454 trucks are hydroboost. Wouldn't worry about 109 or 110 lsa.

Some port cleanup probably can't hurt, just be careful on the intake side past the injector port, I've read that going too smooth can hurt fuel evaporation with port injection. Take that with a big grain of salt, I never looked into it too much.

There should be a block off plate for the egr somewhere on the internet? Or perhaps a plug? Either way the tune can get rid of it.

 

[Dinkster]

The truck will be used for towing and DD. I found an Eagle rotating assembly on Ebay from a guy who changed his project plans. It included, new in the box, Eagle crank and rods, KB pistons (.030 over), Clevite bearings and Hastings rings for $900. The only problem with it is the small domed pistons. If I were use them with the Vortec heads (99cc chambers) would have put my CR way too high. So I decided to run a set of the Skip White aluminum heads which, by the time I figure in the machine work, springs/materials, etc i'd have to do to the stock heads, the aluminum heads at $950 are only a few hundred more. Plus, with the 119cc chambers, it will net my CR at around 9.75 to 1. I plan to run the Comp XR270HR-13 cam. I figure with the engine being 489ci and a roller cam, I shouldn't have any difficulty with the FI. And besides, Comp figured that would be a fair recommendation for the combo as well. By the time I'm done, I should be into the whole thing about $3500 - $4000 dollars. I probably could have done it cheaper if I stayed stock but wheres the fun in that.

 

[Supercharged111]

Got a link to the heads? Are they for GenVI?

 

[L29Sub]

Most questions are answered, but I used a Q'jet sitting on a Warrior dual plane. My major gripe with factory engine was the tedious FI layout and lack of torque and reasonable gear splits. I fixed that...
Fuel mileage was about the same...with a lot more useable towing torque. The cam has a hint of rump. Not enough to bother a stock converter. I ran a manual 5 speed. The 489 conversion gave huge 1800-4000 RPM torque bump. I towed 6K in 5th all over NC. Only downshift in the mountains. The engine setup is not going to make a drag racer. It will still be a 6500 lb tow vehicle. And, in that RPM range, exotic porting is useless. Clean and go. Vortec heads are good items. I had calculated 10:1 CR. Cam overlap allows higher CR...slightly higher.
The cats and EGR can be deleted, but deleting them requires a tune. Once deleted, it will not pass emissions. Be advised.
I believe the rotating Scat kit was about $2500. There's a right good bit of spending beyond the Scat stroker kit. And a good bit of knowledge required to correctly fit bearings, rings, and machine work. The block does not require relief. Square it up, nice quality 1rst bore fitting to pistons. And go with minimum recommended clearances on the pistons/cyl if you want it quiet. Break it in reasonably. Use correct assembly lubes, and be super clean. Roller cams are easy to break in.
Be sure your cooling system is 100%. Run 195 thermostat if you want the heater to work.
I bought a 12k toy hauler and finally overloaded the chassis. The burb pulled it ok, but the weight was too much for the Suburban. Had zero problems with the build. Liked the manual trans too. 6000 lb Camaro!
I'll add that when considering all the mods and required tunes and retunes....you see why I did a carb. Q'jets are excellent carbs. Easily adjustable, and dependable. Vortec ECMs are limited. Be sure and chat up your programmer in order to understand the Vortec ECM limits.


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[Dinkster]

@Supercharged111 Skip white performance. They build off of the Proform bare head and say they will work on Gen VI blocks with a Felpro 1017-1 head gasket. https://www.skipwhiteperformance.co...port-aluminum-heads-assem-bbc-oval-274_92785/

@L29Sub I have a 7000# travel trailer that I tow so I'm not looking too extremely heavy. Since my truck is a 95, I will be using the TBI for the time being. Just had the 4L80E rebuilt so I'm not looking to swap to a NV4500 just yet. I know the TBI will be a limiting factor but I figure it will work long enough till I can put together everything for the MPFI . I don't want to do the engine swap and the MPFI conversion at the same time, just more complexity all at one time. I will probably have another custom chip burned for this engine to hold me over. Worst case scenario, i will pick up a TCI trans controller, a Qjet or Edelbrock, and an HEI to get her down the road for the time being.

 

[Supercharged111]

I don't think you'll need a trans controller if you go carb. I want to say as long as the PCM gets an RPM and TPS signal it'll still run the trans. The flip side is your new motor may have longer legs so the stock shift points may come up a little short. The intake will likely be the choke point if you keep that stock.

 

[L29Sub]

If you must have MPFI, find a Vortec 454 donor. All these reco's are based on Vortec.
I used an NV3500/NP241. 4500 is too truck like. They can swapped if same slave cylinder style is utilized.
I would guess (might be wrong on this) that the transmission will enter limp mode if fuel system goes down. Some inputs can be returned or emulated.
Your tuner can advise. I'm not knowledgeable with TBI.
On a Vortec, the auto trans and transfer case can be unplugged, manual trans installed, and the engine will function normally. Doesn't require any trans or VSS inputs.
A 4L80e can easily be managed with a stand alone TCM and a TPS. These are things to sort out before removing parts.
Then there's Fitech. It will work...most of the time. ;o)

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[dAT OBS]

I’ve built a few of the GEN 6 blocks. The best block for a performance build on a budget. They have primary oiling of the mains and rods so oil starvation like the other blocks. Only downside is there is no room for a double roller timing chain if you keep the front crankshaft position sensor and the cams are different. I had a special turbo cam ground by Comp and they sent me the old bolt pattern and no fit. Also the head gasket is different for the vortec heads.

On the timing cover part..any information on not running sensor in time cover can I swap to gen 4 or 5 timing cover with drilling more holes ???