Fast355

iTrader: (2)

Well about 7 weeks ago, my uncle GAVE me a beat-up 1994 Chevy G10 shorty 110" wheelbase cargo van(retired it out of his fleet) to work on and keep. It came complete with a bad fuel pump, 279,418 miles, and obviously needing work. The van was equiped with a stock TBI 305, 4L60E, 3.73 posi, nearly new 225/75/R15 tires, and weighing a horendous 4,800 lbs with a full tank of gas(My conversion is only 5,300!). I decided to put this truck through a few tests to just show how these TBI engines hold-up, run with just the correct tune-up, and mild bolt-ons.

After replacing the fuel pump with the customary TPI pump(new filter and strainer), I started using it for chores. It ran decent, well compared to my 350 it is a wimp, but it has to start somewhere.

I only had two test criteria. Number one was running it at the local 1/8 mile, 4 times in each configuration and average the results(all categories are averaged from the 4 runs, 20 1/8 mile runs total!). Number two was speed at the crest of a 6% grade approximately 1 mile long with a 4,100 lbs 26 foot boat in tow(on the way to the lake every weekend). THe speedlimit is 70 and that is what I am running at the bottem. My 1983s 350 TBI is able to make the hill at 70 MPH in 3rd gear with plenty of pedal left.

In stock form launching at idle (600 RPM) and leaving the shifter in Drive (4,500 WOT upshifts)it ran the following. Not bad for stock!

060'---02.61 @ 16.53
330'---07.47 @ 41.46
660'---11.67 @ 58.73
Hill Climb = 57 MPH in 3rd gear

Next, I did a full tune-up. Cap, Rotor, Wires, AC Rapidfire plugs, PCV, air filter, and a general lookover. The compression test gave good numbers, especially for the mileage and oil pressure showed very strong on my test gauge. I returned to the track.

060'---02.57 @ 20.32
330'---07.31 @ 44.13
660'---11.36 @ 58.26
No Hill Climb (took the 83 and some friends)

The next step was to raid the garage and toss on some spare parts. An open element air cleaner, a 1" 2 hole TBI spacer, an ultimate TBI moded TBI, an adjustable fuel pressure regulator (14 psi from 12), and some chip work on the PCM. The shift points were bumped to 4,850 and it had no problem pulling to them.

060'---02.55 @ 20.92
330'---07.25 @ 45.83
660'---11.25 @ 62.27
Hill Climb = 64 MPH in 2nd gear

I then swipped a box of 1.6:1 roller rockers out of my garage and they found their way onto the little L03. The L03 now liked being dragged all the way up to 5,300 RPM before shifting @ WOT.

060'---02.55 @ 18.83
330'---07.14 @ 45.92
660'---11.05 @ 62.35
Hill Climb = 67 MPH in 2nd gear

On the 6th week the waterpump decided to spring a leak. While replacing the water pump, a leaking timing cover gasket and oil pan gasket were fixed. In the process, I found that the timing chain was very stretched. Its a wonder it hadn't come completely off. I replaced the timing chain with a cloyes double roller with a 3 way key-way. Knowing how weak the factory 305 cam is, I retarded the cam timing 4* (don't forget to advance the distributer again). The 279k AC Delco fan clutch was trashed and a HD fan clutch bolted in its place (was running hot). A 180* thermostat was installed during this round as well. I returned to the track with shift points set all the way up to 5,600 rpm (still pulling hard). BTW, on these runs the HD fan clutch was engaged for 200+ feet on each run(but then again it was laying in the garage after my 1983 was converted to electrics).

060'---02.55 @ 19.24
330'---07.07 @ 49.26
660'---10.95 @ 63.47
Hill Climb = 70 MPH in 2nd gear

Doesn't look like much on paper(-0.72s and +4.74 MPH in the 1/8), but the way it runs is MUCH improved(shown by the +13 MPH hill climb runs). In traffic, you mash the pedal and it actually takes off and goes! Fuel mileage is hovering at 17-19 mpg, 18.32 over the last 3,500 miles(the 22 gallon tank leaves alot to be desired as my 83 is 38 gallons). The engine burns nearly no oil (280,000+ miles). It recently passed the dyno smog inspection with flying colors. The van is now at 283,309 and still counting and I am at under $500.00 on the whole truck.

For comparison here is what my 350 runs(remember it is a conversion on a 125" wheelbase and weighs 5,300 lbs).

0060' = 02.15 @ 33.93
0330' = 06.67 @ 58.76
0660' = 10.25 @ 71.23
1320' = 16.18 @ 87.95
Hill Climb = 75+ in 3rd gear