get more tourq out 454
 

I have a 87 GMC R3500 dually with a stock 454 big block from factory I was wondering what could I do to get more tourq out of the 454 and should I bore out the engine

Re: get more tourq out 454
 

Some more information would help determine the best steps for you to take.

How stock is the motor now?
Its an 87, is it TBI or has it been changed to a carb?
Does it have stock exhaust manifolds? Headers?
Does it still have emissions equipment? Will it need to pass emissions testing?

There's quite a few things you can do, but providing those things would be a great start. Plenty of knowledgeable people here will be able to chime in. I'm in the middle of rebuilding my 454. There's a threat for it on here. I'm having to adhere to smog regulations as I am in CA, but it may be worth a look anyhow.

Re: get more tourq out 454
 

Cam swap....if you had one thing to do to be effective.....that takes advantage of all available lift in the valve springs pre-valve float..............

Re: get more tourq out 454
 

Its stock TBI 454 with stock manifold and yes it has the emission equipment and yes it hat to pass the test

Re: get more tourq out 454
 

Heads. Cam profiles in tbi applications are very mild so that the ecu can account for them and most chips or tunes are not emissions legal. I would find better heads or port what you have and look into perhaps a good set of headers.

Re: get more tourq out 454
 

Vortec heads, exempt cam, legal headers (and duals if legal), and a stroker crank are about the gamut. I don't know how hard it is to tune your ignition advance without a chip but it would help alot.

Next step would be lower rear gears.

Re: get more tourq out 454
 

If torque is mainly what you're after, your stock peanut port heads are ok for low end, porting them helps a lot.

Headers will help quite a bit. Hedman makes great smog legal sets, in fact they were the only ones that had them for a 4x4 454 truck. I don't know if your truck has A.I.R. pump or not, but they have headers with the tubes for those.

I'll second the recommendation for a cam. But also agree that the TBI cams are fairly mild. Some advantage can be had going to Hyd. Roller. Comp cams has good options that make low end torque, and play nice with computers.

Stroking it is also a good option, although it isn't too difficult to outgrow the capability of the TBI injectors.

Definitely address the less than stellar compression. Speed pro makes affordable pistons with varying dome sizes. These 80's 454s wake up quite a bit when you improve that abysmal stock CR.

Re: get more tourq out 454
 

The bbc vortec heads will increase compression one point and produce more torque than peanut ports, if you can find them. You don't want much cam , but you want all the lift you can easily get in a new cam.

Re: get more tourq out 454
 

^ L29 heads (702 closed chamber if you can't find Vortecs), headers and a towing/RV type cam.

Re: get more tourq out 454
 

What kind of a FT/LBS number are you looking for?

You can keep a very street-able 500lbs with a 468

You can also go low compression street-able 496 with 550-600lbs or high compression to get into some crazy numbers.

I was looking for 600ft/lbs because more then that and you get into expensive clutches. I decided to go a smaller route engine wise and make the torque later in the drive-line. It keeps many things cheaper and living longer.

A truck is a system not just a engine.
Torque can be made in many places besides the engine. I am running 4.56 gears because it allows the most torque at highway speeds. A transmission(or multiple) that provides a higher final torque at highway speeds with the right gearing can make a 6 cylinder pull away from a v8.