I have a 1990 W250 extended cab with a 5.9 tbi engine that is gutless and poor fuel economy. I was wondering if I built the motor to a 408 stroker if it would work for a towing and everyday driver?

 

honestly if your thinkin about dedicating time and money to the thing id just do a cummins swap....go big or go home right?

 

I've considered that, however, everything has to be changed. Axles, transmission, fuel system and so much more. Just was thinking a 408 might be easier and cheaper

 

well if you could find a donor truck it wouldn't be that bad...
why you gotta change axels? if you bore it its gonna have the same axles anyway... and tranny... im curious how much do you intend to haul with this thing?

 

reason I ask s I have a 87 318 carbureted and it easily hauls 5000 with a good trailer... plus a full bed and that's only a half ton truck with stock suspension nothing is beefed up and my mileage drop is almost unnoticeable and its got plenty of power to do it

 

What size tires do you have? You might just want to consider regearing. You could have 600 hp but with the wrong gears it will still feel gutless.

 

If he was to switch to diesel: typical 1/2 ton axles are undersized to hold the weight and torque of a cummins. The diesel trucks had D60 axles (or D70 in rear)

 

My truck has dana44 axles w 8 lug set up, I'm running 4.11 gears and when I pull 4500 lbs I'm to the floor with my gas pedal and will not go over 65 to 70 mph. My tires are only 1 step oversized and are narrow. They are 31" tall. The transmission is a 46rh and I never tow in overdrive, even if I could I wouldn't. If I was to put a 6bt in it, I'd want 3.73 or 3.55 gears. The 4.11 gears set wouldn't allow any economy on the freeway and would be topped out against governor @ 70-75 mph.

 

I would like to be able to pull 5,000 lbs, but as it sits with the 5.9 gasser motor I can't get up to speed in a mile and I have the pedal to the floor pulling less than 4,500 lbs.

 

oh... wow that's kinda pitiful... i have dana 44 front and Dayna 60 rear so yeah... plus ive only got the 727 tranny so ive got a way different setup in there


but still if you bore and stroke it its gonna get crappier mileage regardless.. if you can somehow get more torque outta the thing go for it... ive considered changing mine up to be a 340 for a little more power.... id consider re-gearing everything cuz like sls011 said you might have a lot of power but with the wrong gearing for what you want it to do its gonna feel like nothings there