Author Topic: 83 silverado drivetrain, anemic, ideas on swap??  (Read 2191 times)

Offline mrjata

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83 silverado drivetrain, anemic, ideas on swap??
« on: August 30, 2015, 11:25:36 AM »
Just got Mom an 83 silverado, has the worst of everything in the drive train to me.  305 w/lockup 350 trans.  Won't pull a dead cat off the sidewalk.

I have a 350 and a short shaft TH350 in the stand.  Ideas?  Think it is cheaper to go with a longer driveshaft than get a long tailshaft TH. 

One wire Dist too, ick!  Time to simplify things again.  Oh ya, Holley for me.  None of this perdy Edelbrock stuff.

Not fond of headers either.

Ideas??  I know you guys have all been there and done that. I appreciate the comments.

Offline VileZambonie

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Re: 83 silverado drivetrain, anemic, ideas on swap??
« Reply #1 on: August 30, 2015, 11:45:16 AM »
Not sure what you think you'll gain by going from a TH350C to a TH350 other than worse fuel mileage.

If you have a 350 kicking around you will notice a major improvement over the 305. Your best bet would be to find out what the final drive ratio is and put in a set of decent gears matched to a 700R4/4L60. What size tires are on it? This is a C10?

What do you mean one wire dist?

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Offline mrjata

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Re: 83 silverado drivetrain, anemic, ideas on swap??
« Reply #2 on: August 30, 2015, 10:57:32 PM »
The drive train in this truck now is slugish, won't pull anything and the transmission "locks up" at such a low RPM, it is gutless to pull even the smallest hill.

As for mileage, it gets about 15-18 now (prob a 3.08 gear) and I got about the same with a 350/th350 (w/Holley, cam headers and a load)

If you think the transmission is alright, that will save me a lot of headaches.  Doing some homework on how the "lockup" works.

the distributor has several wires running to it that I don't understand yet.  All the rest of my motors have one hot wire to feet the dist.

Still sorting out the vacuum hoses.  I only need 3, dist, trans modulator, and the blend door. 

Please correct me if I am off here.

thanks for the reply.......

Offline mrjata

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Re: 83 silverado drivetrain, anemic, ideas on swap??
« Reply #3 on: September 01, 2015, 11:45:49 PM »
I am going to try to disable the lockup part of this transmission to see if it works any better.  I guess winter is a good time for a motor swap.

Offline Stewart G Griffin

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Re: 83 silverado drivetrain, anemic, ideas on swap??
« Reply #4 on: September 07, 2015, 07:13:16 PM »
Check to see what rear diff gears you got.

Check to see if the secondaries are opening all the way.

Offline mrjata

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Re: 83 silverado drivetrain, anemic, ideas on swap??
« Reply #5 on: September 13, 2015, 11:11:24 PM »
Checked the "quadrajunk" and the secondaries are opening.  Checked timing, right on the money.  Since I have all these parts on the shelf, I wonder if it is worth putting on my aluminum intake (Holley 300-36) and a Holley #3310 (750 vac. sec.) on this 305?  It shifts so fast, by that, I mean at very low RPMs.  The converter locks up almost immediately.  At normal throttle, accelerating, it locks up at about 40 mph. feels like about 2k, maybe 2500 max. then if I hit a hill, I have to manually drop it down a gear.  Sure, I figure the kick down needs to be adjusted.  On my 350s and larger motors, I never hooked the cable up, never needed to.

Just getting frustrated, mileage is not much different than any other truck, average 16-18 mpg.  Just gutless!

Thanks for the input, OH, the gear is a 3.08

Offline c10fan

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Re: 83 silverado drivetrain, anemic, ideas on swap??
« Reply #6 on: September 16, 2015, 10:48:09 PM »
A 3310 is way to big for a 305. Leave the qjet on there. You can send it out for a rebuild to Sean Murphy Inductions. He does a great job from what I hear. I had a 83 c10 with a 305/700r4 and they are gutless. Not really known for being a powerhouse. There are things you can do but it might be easier to swap in a 350. you can get a new 260hp 350 from GM for $1200-1500
Anthony