I’m pretty sure there are threads on this topic already but need help. I have a 2004 4x4 with 5.7 with 250,*** miles. Starting to get blow by in the cylinders, oil residue on the air cleaner. Since I’m going to eventually put an engine in my truck, what are the main things to swap in a 6.1? I’ve read some older posts from like 2 years ago about this but as far as mounts and all, that’s all pretty much the same. What accessories, sensors, and wiring needs to be updated?
Well, that all depends on how much of the 6.1 you are insistent on using and how fat your wallet is.
Ok so insomnia set in and I got bored. So, first question is do you have a line on one or have you researched how much it's gonna be to get one? Because they stopped making them at the end of 2010 and they were rarer engines during production than the millions upon millions of 5.7's that made their way out the door. They're not cheap, long or short block.
Next question, how much of this were you intending to use, which goes hand and hand with how much power were you looking to get out of it? Just a little bit more, or ALOT more, enough to start giving your RFE fits and eventually break it?
There are a few ways this can work. Essentially a 6.1 is just a much better built 5.7 with bigger bores, better heads, longevity tweaks BUT....designed for cars.
Easiest method (also cheapest) - Get the short block, use stock style 5.7 heads, use your front timing cover so all your accessories bolt up and since you're using stock style 5.7 heads the intake manifold will bolt right back on. Also need your stock oil pan and dipstick, car version won't work in a truck. Get a different cam, as the 6.1 cam is terrible for a truck. Now you need custom tuning (by the way, the minute you wanted to increase displacement custom tuning was pretty much a given, also depending on which cylinder head you use EGR may need to be written out of the tune so you don't get a CEL). This type of swap has been done many times, everything bolts in like factory and you get a displacement increase with a stronger bottom end. Indy cylinder head offers an engine just like this (but carb'd) that is good for 400hp with stock 6.1 cam. You'd get better results with a cam better matched to a heavier vehicle. By the way, this engine from them is about $8000:
http://www.indyheads.com/6.1hemiengines.html
Harder method (also more expensive) - you insist on using the entire long block (with 6.1 heads). Yes, the 6.1 heads are better heads and will net better power IF you can properly take advantage of them. This means an exhaust system that matches (port differences both intake and exhaust between early 5.7 and 6.1 heads) and intake manifold. You
can use your stock 5.7 manifold, but 1) you need spacers to make it fit correctly (aforementioned port mismatch) and 2) that intake manifold will be your choke point and those heads won't really do you any good. You
could use the 6.1 manifold, but that requires either modifying the front timing cover to move the alternator and A/C compressor out of the way for clearance and switching to an electric fan (no room for clutch fan anymore) or converting your accessory drive to the car version, which will require all kinds of harness lengthening, custom hoses for the A/C system, notching the frame for clearance, changing the cooling system, etc. As I mentioned earlier, EGR may be a factor. 04 1500 5.7 has EGR; 6.1 does not.
Best method (and cheapest/most cost effective) - take your stock 5.7 block and get it stroked out to a 392. May actually be cheaper than trying to get a 6.1 to work in your truck and will net better results. Even with the stock style heads (could always P&P and add bigger valves) you'll make more power in a better way (6.1 is a big bore somewhat short stroke engine designed to rev, stroked 5.7 out to 392 has smaller bores but much more torque producing stroke on top of more displacement) with a completely forged bottom end. On top of that, everything will bolt up like factory, accessories, intake, etc, though better exhaust would be a good idea. Once it's all back together you could tell people it's a stock 5.7 and depending on what type of cam and exhaust you have they might actually believe you lol.
Downside of any of these plans is the fact that the 545RFE (your transmission) is ok as long as you leave the engine itself stock. You start putting any real power improvements and things can go to hell rather quickly. Plus the RFE is a power sucker, it's amazing how much power you lose from the crank to the wheels.
Any questions lol?
