'98 4.3L destined for propane...?

[WRMorrison]

I recently bought a 4.3 Vortec long block (and some other stuff...thanks BeRowdy!), with the intention of building it for propane use. Problem is, I've only built a few engines before (all small blocks) and none of them were propane. I think I've read somewhere (after enough "searching" your mind turns to mush) that propane engines run better on higher compression. Is this true? I don't think that I'm going to need new pistons, so should I consider raising the compression by milling the heads? I'm no engine expert, but I'm pretty handy with machinery.

Also, does anyone make a propane kit for this engine? I've looked, but only found kits for the V8's (at least for GM). I'm on a really tight budget, so I might consider piecing together a kit with rebuilt parts.

Next question, (thank God for the Newbie section... :laughing: ). I'm still a bit confused on how propane engines work. Does the propane get injected into the carburetor, or is there something that takes the place of the carb?

One more and I'll quit bugging y'all for a while. This engine obviously came with F.I., but that's long gone. Is there a 4.3 intake out there (that will work with the Vortec heads) that was made for a carb? I'm going to the local salvage yard on Tuesday, and don't want to wander around like I'm lost. I'd like to at least have a clue as to what I'm looking for.

Any tips, tricks or advice from the folks who've done similar?

Thanks in advance,
WRM

[getstucksome]

I have no idea about any of your questions, but have heard good things about gotpropane.com. I'm think if you email them they'll be able to work with you and help you out. I didn't see a kit for the 4.3 though. btt for ya

[Propane]

I do custom projects for rockcrawlers. Just not street legal trucks. I've done several vortec 4.3's and they run awesome! No need to change intake manifolds. The propane mixer goes before the throttle plate of the existing manifold. Just unplug the wiring and throw it away. :smokin:
I always say it , if you add up all the parts to do a conversion, it gets pricey. New or used. Many people fall into thinking that a propane kit is $300 used. There is a lot more to it than the mixer and regulator. Also used equipment uses more fuel. I can probably do it for around $950 to $1000. Save the money digging into the motor and do the fuel system correctly. Why build a motor for 'pane, spending $$ in the process just to put older equipment on it? With my stuff you'll be done in a few hours and it will run right the first and every time. Guaranteed.

[WRMorrison]

I see what you're saying with the used stuff, makes sense. I'll just have to wait until the engine is ready and I have the funds. Do you know what years of vehicles I should look for to find an intake manifold? Mine doesn't have one, but it does have the vortec heads. Also, what about the compression ratio, does it really matter? I've gotta rebuild the engine anyway, (for piece of mind if nothing else) and it would be a lot easier to toy with the comp. ratio now than later.

I'll probably get the kit from you since you're local and obviously have much more experience than I do.

-WRM

[Propane]

I didn't see you're local. Call me 480-430-8033. Yes, if you're going to build it anyway, at least shave the heads. If you're doing a full rebuild, 12:1 compression will work great :grinpimp: No gas motor will be able to touch it.
You can use any intake manifold you want. It will run good with any manifold on it. Even those super high rise intakes. :beer:

[chinweasle]

One more and I'll quit bugging y'all for a while. This engine obviously came with F.I., but that's long gone. Is there a 4.3 intake out there (that will work with the Vortec heads) that was made for a carb? I'm going to the local salvage yard on Tuesday, and don't want to wander around like I'm lost. I'd like to at least have a clue as to what I'm looking for.

Thanks in advance,
WRM


I can help out with this part (and save you some money too) edlebrock makes an intake minifold for the vortec 4.3l part # is 2114. I had all the parts bought to convert my 4.3 to carb, but have decided to part it out. I have sold the manifold, but still have the carb and the D.U.I distributer if your interested. (check my post in the forsale section)