I know that 400 may be a dream but I really want it to be as torquey as possible. 300+ ftlbs should get the job done. Above all else I would like an efficient reasonably powerful truck to drive. It will have to be done in stages. I haven't actually finalized the deal on the motor yet. It looks like I will spend most of my budget right now on the swap and some other changes that the truck needs, rear end, some front suspension work etc. But I find it is wise to try to plan ahead. I am sure that it would benefit from some head work, and a cam swap will be a must. But I don't want to over do and end up with more than I really need or want. The truck will never be a real contender for a super fast street truck. It is too heavy and not really suited for track duty. But it can be a comfortable fairly quick cruiser. So I am going to hang around and listen. I will be asking some questions and looking to learn from others prior experience. Jay

 

What year/model truck is this going in Jay? (rcsb/ecsb/ccsb/etc.)

 

87 GMC crew shortie. I am taking out a 454/ 400 combo. I should be able to get better performance and vastly improved mileage Jay

 

I personally think you should keep the 454/400 combo. With a good cam and aftermarket heads, 400lb torque would be very easy to achieve. and if you put FI on that engine I think your your gas mileage would be similar to a modded 5.3. If you really wanted to improve your gas mileage, swap out the 400 for an OD tranny.

 

It is injected. It really needs the full go through. I do most of my driving around town The ls should pay off there. The 454 is rated at 230 hp 385 ftlbs
So mid low to mid 3s in torque would suffice. I think that I can have better performance and the vastly superior engine management system can only improve mileage and efficiency. The 454 is getting tired at 99000 How many latemodels have you seen still going strong a 200000 I am going to change the gear and that will help compensate for the lower torque and the Od is self explanitory.

I guess that the improved efficiency and mileage are the real motivators. Really great performance is nice but a dependable efficient daily driver is a must. I could have just bought a late truck, but that just not my style. I have always driven something a little different and am willing to pay the piper to do it. Jay