Engine swap options

[RockPaws]

Hi All,  My old Chevy Truck 1973 2x4 3/4 T 292 six engine 4 speed been in the family since new in late 72'.  The 292 has been a great motor and still runs great (I rebuilt it about 25 years ago).  Does not burn oil, but lacks the power it once had. Its been a great truck, now just my ranch/work truck for building our new home.  I've also considered a 4 barrel carb and manifold upgrade for the 292?  It already has a HEI upgrade.

I'm considering an V8 engine/trans swap.  I'm looking for better power and fuel mileage. 

Engines? Would like enough torque to support hauling when needed, but not on a regular basis.
Would like multiport if possible, but would consider the reliable throttle body.

Transmission?  So far would like to swap in a NV4500 5 speed, but will consider a automatic.

Best donor Chevy truck?  My best route to get all the wiring and computer.

Any recomendations would be helpfull; links?

Thanks,

Frank

[team39763]

I'm a believer in the BBC now.  I towed my race truck with a Ford truck powered by a smallblock, and it felt like crap.  That poor truck couldn't pull up hills for crap.  Then I bought my 454 powered dually and it's amazing.  I don't really notice the weight back there.  That poor Ford needed to be floored just to maintain 55mph sometimes.  I also like the 4L80E trans, but I bet that 5spd would be nice as long as you didn't have to sit in traffic.

[Lt.Del]

4L80E trans

The 4l80e trans is nice, but, you must have a 91 or later computer to control it, along with the VSS

A nicely built sbc will work just fine unless you are pulling something over say 6k lbs frequently.  With an inline 6 cylinder, you may have a higher rear ratio.  you may wanna consider lowering that.

[78 Chevyrado]

Look up caddy 472's and 500's.  When the time comes I'm dead set on a 500 in my '78 C20.  Higher quality parts, close to sb chevy weight and more torque stock than any 454 came with. plus I see people claiming to get 20mpg with a 3 spd tranny in a 4700lb. car. 

[dustystrucktoo]

 
My dad always tuned his 1972 Buck Electra 225 with the 455 engine, I do believe it was with a 400 tranny, every weekend.  He did get 20 mpg.

You can acquire a cheap engine from a U pull it, usually less expensive than trying ebay or craigslist.  ...  You might want to look for any wrecked local vehicles. 

That straight 6 has the torque, not a lot of power, so any V8 350 or larger V8 will make you happy, even with that 4 speed tranny....  Small carb for fuel mileage. 
The calculation for choosing a carb is listed on the Holley web site. 
I don't advise revving a stock engine past the 5500 rpm, so I tend to calculate 5000 rpm being max for carb selection. 
If you get a 350, go  with the 400 cfm. 
I have a 600 cfm for my 400 sbc and wish I had the 500 cfm .  For a 454 chevy V* the 600 cfm is perfect for full response throughout the rpms. 
More air, requires more fuel.

[Blazin]

What about diesel? A Cummins 6 cylinder would be sweet in that old Chevy?

[choptop]

What about diesel? A Cummins 6 cylinder would be sweet in that old Chevy?

Thats what I want for my crewcab, just got to wait to find the right donor truck ( and the money)
Where did our resident Cummins guy go? Hadnt seen him in a while.

[RockPaws]

Thanks for the replys!
One of my past Chevy trucks had a 454 BB Chevy,  great engine.  Wish I still had that truck! ( a 73' 1 ton 2x4)    Diesel would be great, it must be a Cummins.  But a little pricy for this truck I feel.
 
Maybe the 454 w/ the MPI and a  NV 4500 trans might be the best combo providing the fuel mileage is around 15 mpg. The made these in 1996. Or a 350 hoping to achieve around 19 mpg.
Not a lot to spend on this project so a donor truck would be best.


Frank

 

[rayamx69]

if you are looking for mileage, i would suggest a tbi 350 from late 80s to early 90s, or a newer ls series engine. my 89 burb with the tbi 350 got 18 mpg city, and my c10 with a 5.3l carbed setup gets 15. an injected ls motor should get 20-25 mpg and and are getting pretty easy to find with low miles for cheap.

[Chevalade]

425/472/500 caddy......th-400 with a gearvendors overdrive. Pull houses down, and still get decent milage.

[Lt.Del]

i would suggest a tbi 350 from late 80s to early 90s, or a newer ls series engine. my 89 burb with the tbi 350 got 18 mpg city, and my c10 with a 5.3l carbed setup gets 15.

Ray, you are correct there!  My 91 sub 3/4 ton 4x4 tbi 5.7 gets 17 on the interstate with a light foot.

city driving though, well, that's a different story to get that detroit metal up to speed 5 or 6 times a mile. Lucky to get 11 then--with a light foot