I'm new here, I have a 98 dodge ram 1500 ext cab 5.2 V8. I purchased a MagnaFlow exhaust system single insert and dual rear exit. If I was too add a k&n intake system how much of a difference in power would I notice after putting 800 dollars in the truck?

 

Nothing. Welcome to the forum.

 

Yup, the stock cold air intake does a good job, won't see any performance gain from changing it.

Only way to get a lot more power is build a 408 stroker, or get a blower or turbo. But all of those are spendy.
Another option to get the truck moving easier is regear the differentials to 4.10s, think I may do that eventually. But again that's spendy, (times 2 if you have 4x4).

You could do little things over the years like I did like roller rockers, intake, cam, tuner but it won't add much more, only like 50hp with everything combined.

 

Will I notice a big change adding 4.10 to the rear?

 

Best bang for the buck would be a tuner. Even a canned tunes tuner like a Superchips will get you about 20 HP & 30 TQ. Seen some pre-owned ones for your truck for around $150 on fleabay or around $300 new. Used works just as good, just make sure original owner returned his truck to stock before purchasing it as tuner only works on one vehicle at a time...

 

Depends on who you ask. Some will say nothing. Others will say moderate. Many will say significant.

Like everything else in life it is not one size fits all. For instance, if you have a catalytic converter that is gummed up from age, and you replace it, then you will see a performance improvement. However, it isn't an increase in OEM listed HP, just in what you are used too.

However, if you put $800 into your truck then you should feel good about that (as long as you can afford it). Whether or not it gives you none, little, or some HP increase.

 

Throw some Harland sharp 1.7 rockers in. And an exhaust. That otta do it for you

 

do you think MagnaFlow and flashpaq chip will do the job for me?

 

Yes, 4.10 gears will be a significant improvement getting the truck moving more quickly. If you plan larger tires in the future then go with 4.56 or 4.86 gears.

Tuner in my opinion won't make a noticeable performance increase, neither will 1.7 roller rockers, but they certainly will help a little. Depends on what kind of performance increase you are looking for, and what your definition of increase is.

If I were to start over with my truck gears would be the first thing I'd do when I had the cash saved.

 

Depends on what you define as doing it for you. No other mod in the $300 range is going to get you 20-30 HP & TQ gains but those modest gains aren't going to take you from worst to first at the track. It's not gonna be in the same league as stroking it or heads or cams with custom tunes but it's not costing thousands either.

As for regearing, I've always been a proponent of it. Regeared my last two Ram gassers to 4.56. But spending $2000 plus (assuming you're paying to have it done) doesn't increase HP or TQ output on the dyno by even 1 HP. Numerically higher gears gives you a greater mechanical advantage thus allowing the engine to get up into the power band faster and keeping it there.

Me, just based on increase per dollar, I'd start with a tuner. Then the exhaust but I'd do a bit more than just the muffler. If inspections aren't an issue - get an inexpensive set of headers, ditch the cats (if originals they probably clogged and choking the system anyway) and go dual with a simple H pipe. Throw a $5 set of non-fouler on to eliminate CELs and call it a day. If you have to endure inspections, replace the cats with a set of MagnaFlow high flows.

If you can do the exhaust yourself, your gonna be under a $1000 total for the tuner and dual exhaust complete with headers. It's gonna be tough to beat those gains for such a small investment, IMO...