94 2wd vin 'Z', What is a reasonably easy swap?

[Coyote X]

Well the trans died in my van from a leak in one of the steel coolant lines. So I figure if I have to pull the trans I might as well pull the motor and stick a v8 in there. So my questions are what would be a good drivetrain to fit in it?

I am wanting something strong to tow with and not totally kill my mileage. I currently get 22mpg driving around empty and ~15mpg towing 4000lbs. I don't mind going down a couple of mpg but I don't really want to drop below around 19mpg driving it easy.

Since the motor and trans are both going to be swapped I could go the easy route and stick in a 94 5.7L TBI. But I have no idea what kind of mileage or power I am looking at with a swap like that though. I would probably just leave the 4.3 in it instead of living with 16-18mpg normal driving. I am never in a hurry towing with it so going slow up hills is not that big of a deal. I guess other options are a LT1 or LS1. Those motors would probably get better mileage but I am not sure if the work getting them mounted would be worth the possible gain they would give over a plain old ~94 5.7L engine.

My ideal setup would be I guess a strong reliable V8 with a built 4l60e(maybe 4l80) and 12 bolt. With good steel springs and a reinforced frame that ties the subframe and rear frame together with the hitch. That way I can tow pretty much anything short of a gooseneck trailer. So is there anyone that has done the swap to a V8 that has some ideas for me? I am probably looking to start doing something in the next few weeks and try and get it done by Dec, so I am not in a huge hurry to have it running again. I just want it done right so I won't have to look at it again for 100k miles or more.

[mikedamech]

I put a 95 LT1 in my 98 Astro, it was easy for me having all the tools, made the exhaust. Mounts from JTR $50, wield rear mount, use ECM and wiring from donor vehicle. No highways here only city driving I get 17 MPG, same as the 4.3. I put a 95 TBI in my wife's 94 and reused the mounts, rewired the stock ECM was easier than the LT1. I don't know the mileage, she won't set the trip meter. Pulling a trailer seems better now but the 4.3 was an animal too.

[Coyote X]

Well I ended up putting a junkyard trans in the van to get it rolling again. But now with warm weather it is time to dig this idea back up. I will be taking my stock trans in this week to have it beefed up to handle anything I can throw at it hopefully.

A buddy also has just given me a 350 out of a 95 or 96 truck. It has the throttle body on it as well as most of the distributor. So I just need to get the right distributor setup for a 94 spec setup and adapt the throttle body wiring to my existing wiring. But one big problem is I have no idea what chip to use in the computer. I have not been able to find out what bin file is used in the 94-95 5.7 engines. Anyone got any ideas?

The engine ran find but it smoked a bit so I figure just freshen it up with new rings, bearings and seals and it should be as good as new. I will probably just buy the brackets from JTR to mount the motor. So once I find the proper bin file I should be able to order one from GM or just get the stuff to burn it myself and be ready to start on the swap.

[astrozam]

Just wanted to clarify you're motor designation because I always thought the 93-95's were the W motor knowing whether this is sometimes not the case would be good in helping others in the future, thanks

[rlsllc]

Just wanted to clarify you're motor designation because I always thought the 93-95's were the W motor knowing whether this is sometimes not the case would be good in helping others in the future, thanks

the "Z" was still around up until 1994, I have a 1994 cargo with that motor and no hydroboost.

I think (and could be wrong) that all 1995 vans were the CPI "W" motor, and the '96-'02 were the new CPI "W" with the plastic upper manifold, and the '03-'05 were MPFI "W" motors.

[Coyote X]

Mine is a Z with the throttle body. The 350 I have I can not guarantee what year it is and as of right now it is just sitting on a pallet in my garage. The 350 is a throttle body engine with a flat aluminum distributor base. The electronics have been removed from it so I just have the shaft and base to mount everything inside it.

I will tear the 350 down in the next couple of weeks and try and figure out exactly what I have. I can get a new distributor pretty easy if the one I have now is wrong so that is no real problem.

I am thinking of just getting the APU1 AutoProm from Moates.net and just start with my existing program and just fix the number of cylinders since it seems pretty hard to find a bin for what I need. It looks like every combination has a different bin, even for simple stuff like a different rear end gear. I can take the wideband off my other car to use to tune this van back up and get it running good hopefully. I have never tried tuning an obd1 system but it looks very similar to the megasquirt used in my other car.

[Mr_Roboto]

Start with a 350 PROM and work from there. the gearing is probably due to the chip but would likely be easier to fix than fuel or spark tables would be.

[1Gary]

Take the casting number off the top rear part of the engine above the flywheel and look at this link:

http://www.mortec.com

That will I.D.the engine for you.Also the number of intake bolts tell you which engine you have where 12 intake bolts are for the early yrs(95 and below) and 8 intake bolts are for 96 and above.Paid attention once you have the intake off.Hoping for you that it is already a roller engine which you can tell by the roller retainers on the lifters.I think the roller engines are better.If it is a 1995,you could have the bosses already there taped for the bolts but using a hydro flat tappet cam.It's worth getting the spider retainer and bolts for the roller cam conversion.That is something you could get at a pick and pull junk yard engine.The thing about that is O.E.M. spider retainer do wear and have a limitation on RPM ranges and if it where me,with that I would never go beyond 5,000 to 5500RPM.After market spider retainers you can get and might be worth a look.

Take off the valve covers and get the casting number off the heads to see which heads you have as well which you should be able to find in the link above.

Please continue to update us and of course pictures are always welcome.

[Coyote X]

Ended up putting the rebuilt stock trans back in today. The cheap junkyard one was not doing well and pretty much has given up taking any power in 4th.

The trans now has a beast sunshell, red clutches, 5 pinion, billet servos, etc.. and a 1200 stall diesel converter. I bet I can't kill this one as easy. I would have waited for the 350 to do them at the same time but I was wanting to wait till may to do the swap and the junkyard trans probably only had 100-200 miles left before it died. The 350 is still sitting in the garage waiting on a rebuild and build up.

I guess as of now my plans are to get it built to a low rpm grunt motor. Probably an RV cam of some sort. Preferably a roller cam. I will probably advance the cam 4 degrees to keep the power in the bottom end. I am thinking of just deburring and smoothing the ports and manifold. Maybe add an inch spacer to the throttle body. Stock pistons and compression ratio. Jagsthatrun sell a set of shorty headers, I am not sure if they are worth getting but I am really thinking of it.

I just ordered the 4000lb steel springs from stengelbros so once they are in i will let everyone know how they do. I figure they should beat the crap out of the stock 1450lb each fiberglass springs.

Once it is done it should be a pretty tough Astro, especially if I can find someone to paint a giant wrap around mural on it.

[Mr_Roboto]

If you want a cheap cam do the L98/LT1 cam or a stocker Vortec 350 cam. All are huge upgrades over the peanut cam TBI engines used and will make a good lower RPM engine with an improved top end range as well.