Need a new engine and your advise

[Desert1957]

My 83 needs a 5.7 long block. Should I replace what's there or go the LS route?

Only thing that complicates my desicion ( other than Money) is that this is my tow vehicle and it has an SM465 manual transmission.

Appreciate any thoughts you guys might have, Thanks in advance.

Desert

[veinbar]

383 would be the best decision for towing a pulling such a big vehicle around. The LS swap would be amazing, really amazing, but could take ages to complete and twice the money of the 383. Fuel efficiency should be comparable to the 350, maybe better due to improved torque. Just my 2 cents.

[jrcaprai]

If you can afford the LS do it.... but I would suggest the Trans replacement as well

[tucsonjwt]

How much weight and how often are you towing. Personally, I like my SM465 with a gear vendor behind it, but for towing up and down hills it might not be the best. If I were to invest in a modern engine and trans, I think I would look for a newer truck with those items in place, stock from the factory, rather than try to convert my old square.

[Desert1957]

Originally Posted by tucsonjwt

How much weight and how often are you towing. Personally, I like my SM465 with a gear vendor behind it, but for towing up and down hills it might not be the best. If I were to invest in a modern engine and trans, I think I would look for a newer truck with those items in place, stock from the factory, rather than try to convert my old square.

I have a newer truck (04- Z71) , I love my old "Square Pickups" that's why I'm here.

My 83 Silverado is the work horse, 9200 GVW "Camper Special" 410 gears and Stick , It will tow anything. Race car enclosed trailer weighs about 7000 Lbs, Gets towed about 3 weekends a month.

Desert

[88Jimmy4x4]

I would just go back to the same 5.7

[C-10 simplex]

i think it boils down to how much time and money you got?


And, realistically, how much driving/towing in miles per month will you do?


The LS is generally superior to the small blocks/big blocks etc and will probably get much better mpg, but will most likely take much longer to complete.

Simplest easiest way would be 350 or 383, but these don't get the mpg that the ls can.

[mooseknuckles]

If I had a choice, LS motor and trans.

[GmtGmt]

The tried and true 350 you cant go wrong with it. Since you have done towing in the past with this why not just stick to what works

http://www.jegs.com/i/GM-Performance...oductId=752506

The only thing i would add is This to take it into the morden day

the LS is a trend just like the cummins and shortbed crew cab is

[camshaftgsxr]

if your going to buy a long block get the biggest one (383 406 blah blah) you can, however... LS IS the best option if you have the money