Starting to Learn on 95 G30 5.7 for Towing

[Fast355]

Hello, I found this site a few months ago and what a great spot for information it has become for me. I have a 1995 G30 Van (Light Duty, it's really only a 3/4 ton GVW with SF rear and 4l60e) I am using for a tow vehicle. It does pretty good for what I need it to do as long as I am not in a real hurry because there are a lot of long steep hills here in Oregon. I first swapped the differential gears from 3.23 to 4.1 with new bearings and that helped a lot and got rid of the noises from the rear end. I lucked out and found a VSSB from a Suburban with 4.1 gear for a dollar, so the speedometer is spot on now. Next I plan on a few engine and transmission upgrades to a ramjet roller cam and possibly new Dart 165cc heads so a new tune will be needed once that is done. I figured I would break up the tuning part into smaller bits instead of throwing all the parts on and then trying to sort the tune out all at once. First I am going to try to read the stock eprom and burn the same information to another spare 7427 ecm and get familiar with the reading and burning process. That way I have the van and its original ecm in case I mess up and need to use it in the middle of all this. I have done a little bit of soldering in the socket conversion on a Honda OBD0, but had someone else do the chip, so this will be a learning process for sure.

I found this thread http://www.gearhead-efi.com/Fuel-Inj...r-27SF512-Chip from a few years ago and there seems to be some debate over if the socket is needed or not. So I was hoping for some updated advice on that. Also when I go the the local pick a part to look for a donor ecm to experiment with, I am just looking for another 16197427 from a 94-95 V-8 application, nothing else matters, correct?

Thank you for the help!

Weird that you have a 4L60E. EVERY G30 I have ever seen from 1991 and beyond had a 4L80E.

Ramjet is not a bad cam, but far from my favorite. I had one in my Express van and it was only marginally better than the stock cam. I have since traded it for the GM SPO 350 357 HP cam. Also curious why you would want the 165cc head. Those are smaller than the stock TBI heads and probably do not flow enough better to warrant the money. I would look at putting some Tri-Y headers on it or atleast some form of long tube header. Doug Thorley made them for these vans and they still show up on ebay from time to time in decent looking shape. The stock intake manifold, stock exhaust manifolds and stock cam will choke your setup FAR BEFORE the stock heads will.

Finally your 1995 block may not even be roller ready. It may lack the necessary machining to install a roller cam or may even lack the necessary bosses all together.

I would consider something like the Crane Energrizer 260 grind. It works very well on a TBI head engine with the stock compression ratio. It will take some tuning to make it run right, but it would run very strong. Some people may push the use of a dual pattern cam on these setups, however the single pattern grind will make more torque and offers less overlap for a given duration. This allows the LSA to be tightened and even more midrange torque. I like around 210-218* of duration @ .050 and around .450" lift on both intake and exhaust for these engines. Preferably a 110* LSA and 106* ICL.

The 305 Vortec I built for my brothers 1999 Tahoe has a Lunati High Efficiency 268 cam in it. It pulls very strong and has great manners for what it is.