I'm still thinkin' on building an AstroFari tow rig. I have pretty well convinced myself the 4.3 has to go. So I'm thinking about different drivetrains.
Thoughts so far: SBC.
Pros: Done to death, so lots of info out there. Cheap. Readily available.
Cons: Done to death. Puts a lot of extra weight right over the front axle.
Diesel (4BT?)
Pros: Hopefully decent fuel mileage and tow capacity.
Cons: Don't see any info on teh int3rweb, so I'm on my own. Heavy. Probably have to swap rear axles since peak RPM is a lot lower than the SBC. Pricey.
L67 3800 S/C
Pros: A lot smaller and lighter than the SBC, cool supercharger whine, should get decent mileage, readily available.
Cons: pretty much have to do the engine management from scratch (along with the rest of the swap). Have to use a later tranny from a Camaro etc.
What say you all? Am I missing any good candidates?
Jay
New Reader
5/19/08 4:53 p.m.
You can solve one of those cons "easily" by sticking the motor in the back. Lots of room back there...
l67 will require premium.
my vote is sbc.
in fact, unless you really love that truck or the motor's already toast, probably wait to find one already done. They hardly bring more than a normal one. I see two or three a year around here for sale.
What's the weight difference between SBC and 4.3? The difference in power will certainly make up for the difference in weight. I've read that the 4.3 is the worst V6 GM made as far as efficiency is concerned.
What year is your AstroFari? If you find a V8 of the same year, it would make the swap alot easier.
I've got an SBC that I'm going to put in my Sonoma. I lucked out and found a V8 of the same year as my truck, so it's pretty much plug-n-play with the TBI and whatnot, as long as I get an ECM for a GM V8 truck.
Haven't bought a van just yet, I'm thinking any of the Vortec years because the engine wiring is plug n' play. Yeah, I have given up on the diesel or L67 idea (I am basically lazy). My plan is to also get a crunched same year full size pickup, 'Burban etc to make it as easy as possible. I have made ABS a must, either three or four channel.
Next foolish question: you AstroFari V8 guys out there already, should I:
upgrade the rear axle? I'm thinking 11x2 brakes and a 3.08 rear axle (gas mileage).
Which brings us to the next question: what kind of mileage can I realistically expect from this swap? I have heard high teens to 22 MPG.
The new Vortec motors are super cheap used and just as easy to swap in as a regular SBC. Lighter if you get one with aluminum heads, and even the 4.8L is almost 300hp. Even if you spend the $700 for the Edelbrock manifold and LSx MSD box kit you're still going to probably come out ahead when you can get the motor complete with starter and all the belt-drive accessories for under $500.
OOG, edumacate me: when you say 'new Vortec', what years are you thinking of? Are they plug n' play with the older stuff?
Treat me like I'm six years old, 'cause I am not real up on the newer GM stuff's swapability. I'm looking for a reasonably simple swap and since I haven't bought a van yet I can modify my search to come up with a more compatible base vehicle.
4bt cummins will shake out your fillings.
What about a isuzu 4bd1t? www.isuzudieselswapper.com has a kit for the trans. He's saying 30mpg is easy in a pickup.
The newer motors Chevy has been using in their trucks since about 98, the 4.8, 5.3, and 6.0L Vortec motors are pretty much LSx motors with cast iron blocks. Early ones had cast iron heads too, the first couple years, but they all seem to come now with aluminum heads. Everything seems to be interchangeable with the LSx motors, at least as interchangeable as they are with each other, and there's some mix-and-matching you can do with the heads and such for high compression or high flow or what-not. Same engine to bell-housing bolt pattern as all the old SBC stuff, though they use the old top center bolt instead of the middle passenger's side one and they use the "big" flywheel that chevy pretty much only used on the 4.3l in the last few years.
Thing is, they're dirt cheap. Jegs and Summit both sell carb manifolds to replace the stock plastic EFI ones, and MSD makes a box specifically designed to use the stock crank sensor and fire the coil packs without a computer. Even going the carb route and buying new parts I don't think I could have built the 350 I already have in the shop into as potent a short-stroke motor for anywhere near the cost of just buying a 4.8L ready to go.
i've got a 95 and a 96 and the 4.3 powers both of them very well.
IF i had to do one i'd do a late 4.8 vortec truck motor, they are dirt cheap, are available rated up to 305hp (i think the 08's are that), the pan will clear the astro crossmember and the newer 4L60-E will bolt in as well, and there are destructions for converting the truck's harness to stand alone which i'm sure could be used to meld it into the astro harness to make everything work like it should.
an L67 isn't that light.. iron block and heads...
wiring harness from scratch?? not really. Just surf fiero forums , they have put every engine imaginable in them and the info is def out there.
I haver a friend with an S10 and a L67 , he uses the S10 tranny which is apparently quite weak...
Look up a 5.3 from an avalance or tahoe. They can be had for $1000 from car-part.com ..have 300Hp , are lighter than anything you have mentioned and are baby vette motors.
available harnesses are plug and play
JM
86 Fiero GT Northstar 32V
LS1 Corvair.
