305 vs 350

[Jackie Mac]

I have a dilema. I have a 86 chevy with a 305 v8 and a 350 lockup 3 speed trans. The trans is out, and the engine has very high miles. I can get the trans rebuilt and hope that the engine holds out for a good long while. If the engine goes out, I really would like to replace it with a 350 "however" the 350 lockup trans is a little weak for a 350( or so I've been told). I could just fix the trans and forget it but if the engine peters out on me I would need to stick with a 305 instead of a 350, which is really what I want. Any thoughts on this is much appreciated.

[old Rusty C10]

i replaced the motor in my 82 with a crate motor from jegs.. it was worth the upgrade from a 305 to a 350. I have a lockup convertor and my transmission hasnt missed a beat hauliung my boat, gravel dirt garbage etc

[trout]

i loved the 305 to 350 swap n mine tbi

[rayfinseats]

Maybe find a deal on a 350/th350 combo cheap? Shop around. My 83 4x4 was $550 and the 350/th350 works fine. It had a broken rearend. That cost me $150.

[gchemist]

Here is an option. Rebuild the 350th transmission if it needs it. Look for a low milage 96 and later 350. All 96 and later truck motors have roller cams. Remove all the electronics/FI and add an intake/carb. The 96 and later motors have great factory stock heads. You can even swap the cam for a little more power. It's easy to get up 300 HP out of a stock motor.

[dswancutt]

Here is a different take. Does the 305 use an excessive amount of oil, are you hauling or pulling heavy loads? Do you really nead a 350? Fix the tranny save your money and buy a 350 when and if the 305 finnally dies. I had to put a 305 in my 78 4x4 when the 400 ate a lob off the cam. It was the only thing available at the time that I could afford. I have driven the bat snot out of it, and yes it is piss poor on power but I cannot kill it. It can sit for months and starts right off.
For just putzing around or a daily driver, a 305 works.

[motornut]

went threw two 350s when i got it in my 78 burb
first was knocking a bit
ended up a monti 305 worked out ok l stopped driving it for body rot

[gchemist]

Yea, don't count out the 305. Underpowered but good little engine. Mine would still be running if it was not for the nylon timing gears breaking. I ran it hard!! The timing chain is a weak spot for engine problems.

This happens when encased nylon gears break off.

[motornut]

Originally Posted by gchemist

Yea, don't count out the 305. Underpowered but good little engine. Mine would still be running if it was not for the nylon timing gears breaking. I ran it hard!! The timing chain is a weak spot for engine problems.

This happens when encased nylon gears break off.

oh yup seen that....told they did it for noise,
couldn't tell till the chain was off tho,
timing never set up right,
slight line from between teeth down then along under a few teeth that could lift up

[rayfinseats]

"Look for a low milage 96 and later 350." Another good idea!


Nylon gears was a stupid idea huh?

[motornut]

seems like it when everything else connected is steel

[85Bowtie]

Originally Posted by Jackie Mac

I have a dilema. I have a 86 chevy with a 305 v8 and a 350 lockup 3 speed trans. The trans is out, and the engine has very high miles. I can get the trans rebuilt and hope that the engine holds out for a good long while. If the engine goes out, I really would like to replace it with a 350 "however" the 350 lockup trans is a little weak for a 350( or so I've been told). I could just fix the trans and forget it but if the engine peters out on me I would need to stick with a 305 instead of a 350, which is really what I want. Any thoughts on this is much appreciated.

I see you're in Lebanon...only about 25 minutes away from me (you're west of me)...

I would just have the trans rebuilt and get by with the 305 if that's what you really want. I don't think a 350 would be "too much engine" for a lockup TH350 if you did decide on going that route. I plan on swapping a 400 into my '85 with a TH350.

I'll see you at Oktoberfest with one of my Mopars.