well, in light of gas prices...

[FordeatinZ71]

i am thinking about going a different route with my engine plans. i had planned on building my 350 into a 383 and putting it in, which would have made a STOUT motor, but a VERY fuel-thirsty one at that. well, i have always loved mixing new and old and thought i would jump on the "lets put a 5.3 in my 73-87" bandwagon. i know i can do some moderate modification and i'll have almost as much power as i was gonna have with my 383 and i'll still get better fuel mileage. now i just have to sell my 350. i found a rebuildable 5.3 for $300 and the same place sells ECMs for $25. so i am pretty sure i'm gonna go that route and then just build a stout lil 5.3...thoughts?

[daved931]

Do it. If you put some good heads and a cam in a 5.3 with some headers, it'll rock your world (and wreck your tires).

[83K1500]

See I am going another way...
Building the 383 and keeping it carb'd.
No not cause I have a *hitload of money (I wish I did), but because it will be a strict towing vehicle.
I am going into business for myself buying blown engine/trans/head or similar cars that are in good shape, fix, and sell.
So far I have a 91 Civic, 92 Accord and lined up a 92 F-Body, a 94 Grand Prix and looking at two late model Probes.

Hell I only paid $200 each for the Honda's... Which will sell like $1.00 gas once done.

[FordeatinZ71]

i hear ya. i'd love to build a rowdy 383 but i know if i build a rowdy 5.3 i will get close to (or better if i play it right) performance and better fuel economy.

[chubyboy]

if u really want to go crazy, build for e85 bu raising the com. ratio considerably. the reason flexfuel vehivles have less power, etc on e85 is beccause e85 requires higher comp. which would cause SEVERE knock with gas...it all boils down to the whole comprimise theory of stock vehicles, i also believe u may get better gas mileage with the higher comp. ratio, but i am not for certain. HTH

[modular93fox]

do it, i just hit 20.5 mpg in my brick with 3.08 gears... bone stock, nelson perf. tune, full exhuast and cai. good stuff man, way different than a car (to me).
uh, nothing major to look out for other than the costs of money and time. i got jdstevens :) mind made up a few months ago and he did a 6.0 swap :) woot woot..
on a 2nd note.. i passed inspecion with flying colors with a *u know what*..... yeah i was like lets see how it does.. = pass... hells to the yeah!
fordeatingz71 you aughta do the swap.
clint

[GreaseDog]

just because an engine is bigger doesnt mean it will get worse fuel economy. the increased torque of the 383 will have to do less work to move the truck so it very well could end up consuming less fuel to drive the truck.

[GMC Era]

Originally Posted by GreaseDog

just because an engine is bigger doesnt mean it will get worse fuel economy. the increased torque of the 383 will have to do less work to move the truck so it very well could end up consuming less fuel to drive the truck.

His Carbed 383 would not get the mileage a 5.3 would get him. But I agree with your theory though.

[chubyboy]

+1

[FordeatinZ71]

well, my 383 was gonna be fuel injected...and yea, it might have done alright on fuel, but i think the 5.3 will end up being better in the long run. and FWIW modular93fox, you convinced me to do it too...lol. wish you were closer so i could take a ride in that sucker to really see what i should expect. although i plan to put a healthy cam in mine before it gets installed...probably do some other mods to wake it up too...

[GreaseDog]

comparing an injected 383 to a 5.3 is nuts. you're dealing with a truck, and trucks are heavy. the 5.3 is missing something VERY important in a truck. TORQUE. i'll bet the injected 383 will kill the 5.3 in milage in your 4x4.

[83K1500]

Well I will say that with the 305 in my truck WAYYY back when, it was lucky to get 13-14.
Put in 383 and new trans it jumped to almost 20, like 19.something. Shocked the crap outta me I tell ya.
I switched out the 383 for a 89 GTA 350 roller pushing 210K and was back to 14-15 if I stayed out of it. Then the #2 main support snapped, and I am back to slapping the 383 back together and installing it. But as I also said, it will see 95% towing duty with a 5000Lb winch equipped tow dolly so I want it to be able to get out of its own way.

That reminds me I will need to take pics once it is done so that I can show off the new front clip...

[FordeatinZ71]

well, i change my mind like the weather...as much as i'd love the 5.3 swap i'm swaying back and forth now. i'm thinking about just building the 383 i wanted to before. the 5.3 has so much electronic stuff i really worry about it's durability off road. i don't like having to work on my truck everytime i get a sensor wet...so i dunno. it's also tempting because i already have the 350, and it would be a cheaper route to go...i'm not sure yet though...