towing power

Towing a 30 foot travel trailer with my 89 gmc k3500 dually TBI 7.4 with a th400 trans and 4.10 gears. Empty trailer weight is about 6k so figure 7500 with all our stuff in it, plus btwn 1000-2000 lbs in the
bed. Towing it thru the adirondacks.
I did this trip this summer a couple times and the truck does pretty well except on hills. Looking for ways to open this engine up a lil bit for towing. Right now I'm getting 8mpg normal and 6 ish towing and honestly don't care a whole lot about mileage as I only put about 3-4k on it a year.
Truck has just under 130k on it. Runnin real good right now, i've put about 2k into it since i bought it. No money in engine/trans yet, but i've done radiator/belts/hoses/brakes/suspension/etc.
I'm looking for bang for my buck(obviously :)) so I figure the usual easy stuff is out. What I've been looking at are cams/manifolds/heads. I think heads are a lil more than my budget can take. I was checking out the edelbrock manifolds/cams for my engine and they seem reasonable pricewise. I can do all the installation myself for this, I haven't done a cam before but i've done manifolds/heads and luckily my dad has been wrenching on stuff since the 70's so he's there if i need him.
Curious as to what others have done to this engine and what their results were. If i'm overlooking something simple on this engine like headers/exhaust i'd be willing to think about that too.... but i don't mind getting my hands dirty with things like cams/intakes if that's where the results are...
Thanks in advance guys..
Ed
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That engine should have TBI on it and if so and it is pretty choked off on intake side. It will respond well to a better intake and bigger TBI unt. Also while not a fan of dual exhausts on most small blocked trucks with a big block it is not a bad idea. (install a crossover pipe too and stock type mufflered duals will work nicely) I would do these things first before I would consider a cam change at this time. The 454 version you have is a bit of a sleeping giant waiting to wake up. ----------------- TheSnoMan.com
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Yep definitely a TBI, what do you think of the edelbrock intake? The one i'm looking at is the one rated for idle-5500rpm(never rev it that high :)) the part # is 3764
Was thinking about either looking for a bigger tbi or sending it out to get worked on. Has anyone done this/know any good places?
SnoMan wrote:

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A little more info from crawling under the truck. Exhaust is stock cast iron(i knew that) then goes to 2.25" y pipe then to 3" from ypipe the rest of the way back. Single big ass cat and a single muffler 24"case 8"round.
89GMC wrote:

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Okay, if you want a good low buck fix here that will be quiet inside towing and have a bit of a rumble outside at time, get a 3 inch in 3 inch out Flow master or a FloPro. You could also get a single 3 inch in and dual outlet too if you want that but the 3 inch down pipe from engine to muffler flows pretty good if muffler on it flows well too (stock is a bit restrictive) ----------------- TheSnoMan.com
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Actually a flowmaster is on my "wish" list..... may have to bump it up. Now I just need to decide btwn the 40 series and 50 series, i don't mind a loud muffler as long as it isn't rattling stuff inside... SnoMan wrote:

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If you stay with a high flow single, interior noisy and rattling will not be a issue./ Even a 1 in two out muffler will not add muck more noise inside. True dual would be the wost here interior noisy wise and you woul losse a bit of lower RPM and responce with them too (true duals) I would suggest a 50 series SUV or 50 series BigBlock mufflers or possible a 70 series Big Block II. THe Big Block muffler are designed for high flow rates and would play well on your truck with a high flow single. ----------------- TheSnoMan.com
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Good choice for a manifold. Sounds like a good plan

Tell you what, swap out intake first (so you are not cahning to much at once) as TBI is easy to change later. Stock intake is really restrictive ----------------- TheSnoMan.com
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