Darwin -- Future Plans

Darwinskeeper

Frequent Racer
Sep 18, 2005
586
0
16
Wichita, Kansas
Its amazing how much fun Darwin has become now that she actually runs right. Between a defective Holley, which somehow disolved in fuel and junked up the fuel bowls, and an improperly stabbed distributor throwing timing off The 4.3 has been in an extremely poor state of tune for so long I figured that the V6 was just too small to pull the wagon. The carb was eventually removed, disassembled and found to be so bad that Holley sent a replacement free of charge. When the head gasket blew early this year, my mechanic (who was not the one who installed the distributor) was forced to reinstall the distributor and set the timing correctly. Now the engine is actually able to take advantage of the DUI (Davis Unified Ignition modified HEI)'s supposedly optimized timing curve and the car is running better than she has ever run. She is just fast & loud enough to be fun and slow enough that I can enjoy myself without alerting the cops. I'm even beginning to believe that there might be some truth to all that Davis Unified ignition hype.

I'm having so much fun that I've deep sixed plans for an engine swap and am thinking of how to get the most out of what I already have. My first plan (once the job situation gets sorted out) is to optimized Darwin's carburetion. Her best fuel efficiency came right after I had her original 4160 rejetted and had a higher pressure power valve installed. The practical thing would be to use a vacuum gauge to see which power valve I need then take her down to Wilhites and have the new carb rejetted with a wide band oxygen sensor and have a new power valve installed. I'm still tempted to install a new Street Demon instead. The newest Demon seems to have a lot of quadrajettish features (like the triple stack boosters) that could make it the perfect carb for a cruiser. Mind you it could also turn out to be the greatest dead end since the Holley teapot style 4bbl carbs of the 50s, and I'll probably have to get it rejetted anyway. Either way, it would be a good start.

Other plans involve replacing Dar's 3 speed Saginaw with either a Super T-10 or some sort of 5 speed and new rolling stock. While Darwin handles well, I've often thought the current "big & little" 205/60R15 & 225/60R15 tires were a bit overkill. I'd like to try and go with "small and smallers" 195/65R15s and 205/65R15s mounted on a set of Centerline autodrags. Those should still look smart, allow me to make the most of the six's meager hp and maybe even net a little better fuel economy
dancin_banana.gif
 

clean8485

Weekend Racer
Jan 30, 2011
91
0
0
Sounds like an interesting plan. I for one, will be very interested to see how it works out. Thanks for posting your plan, and please keep the updates coming.
 

matty man

Dragway Regular
Jun 1, 2003
1,352
24
38
Grove City , Ohio
Sounds good darwin,, keep the updates coming,, my Isuzu with the 4.3 is on hold due to lack of funds,, i may pull it and put the V-6 & 700r4 into a 5th gen Gran Prix, if I can find one,, Matty man
 

Doober

Moderator
Jun 2, 2003
14,704
1
38
Catalina, AZ
www.cardomain.com
I think while it may be cost prohibitive, you'll get the most out of whatever you're running by going with a set of real ('96+) Vortec heads. The downside is a new intake will be needed though. You would be pleasantly surprised at that v6. A T-10 would definitely be a wiser choice over a Saginaw imo... from my experience it's like puling hen's teeth trying to find replacement hard parts for them.
 

Darwinskeeper

Frequent Racer
Thread starter
Sep 18, 2005
586
0
16
Wichita, Kansas
Doober,

I've actually been debating between the Super T-10 with a 3.42 first gear and an S-10 T5, possibly with a V8 Camaro gearset. Generally the S T-10 wins out on strength, relative simplicity of instl (no modification to the crossmember or changes to the ring and pinion) and cost.

Vortec heads (or even a rebuilt 96 or later V6) would be nice, but that would be something for after I get the El Camino electrified and the 72 Skylark on the road. Hmmm...wonder how hard it would be to drop a 96 or later Vortec V6 into a 72 Buick Skylark. :-k
 

80ECLT

MalibuRacing Junkie
Nov 21, 2006
3,927
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Sheboygan Falls, Wisconsin
Glad to know you have it running properly now! I knew ou would be happy with the power! :)
Grab a 5 speed and put some 3.73's out back and it will be even more fun
 

Darwinskeeper

Frequent Racer
Thread starter
Sep 18, 2005
586
0
16
Wichita, Kansas
I've occasionally considered that. I generally go between the TKO -- which would be overbuilt for a six and would demand trans tunnel work -- and some version of the T5. An S-10 T5 should be able to handle my usual driving style, but I'd be tempted to see if I could get an S-10 transmission rebuilt with a Camaro V8 gearset. Any thoughts/opinions?
 

80ECLT

MalibuRacing Junkie
Nov 21, 2006
3,927
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Sheboygan Falls, Wisconsin
The s10 t5 guts will hold up just fine to the 4.3. No need for world class t5 guts in it. Just make sure you get the 2.8 v6 s-10 trans, so it will bolt up to a chevy v6/v8 bellhousing. The 4 cly trans will not
 

t5montecarlo

MalibuRacing Junkie
Oct 21, 2007
4,632
31
48
Lederach, PA
garage-scene.com
The 4-cyl/V6 T5 uses a 14-spline input shaft, making clutch selection difficult. The only option I know of is an 11-inch disc from an Astro and then you need a larger bellhousing and flywheel. The gear spread on the 4-cyl/V6 T5 is also not as nice as the V8 gearing.
 

Darwinskeeper

Frequent Racer
Thread starter
Sep 18, 2005
586
0
16
Wichita, Kansas
T5montecarlo,

The S-10 ratios may not be as nice as the V8 ratios but they're much better than the 3 speed Saginaw ratios.

I'd heard about the Astro clutch, but hadn't heard that I'd need a new flywheel/bell housing. Makes me wonder how much it would cost to buy a V8 gearset and have it swapped into a S-10 case.

Sadly the updates are on hold until I find my next job. The good news is that I have a few leads and I have till November before I'm laid off. Just wish to have held off until the economy was a bit better.

John E.
 

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