Need a new motor

Seems like an easy question but...

I need/want a little more tq. Not for racing or smoking tires but for towing. I pull a 5000lbs trailer (loaded) about 4000 miles a year. Other then that I use my Hoe to take my soccer gear to practice and carry my rc planes to the field to fly and the once a year family vacation (stuffing the wife and 3 kids into a Mustang isnt easy and I am the only one thats comfortable). So she see's driving duty 3 days a week most of the time. I bought her used (87,000 miles) and now with 169,000 miles the head gaskets blew (3 weeks after replacing a leaking intake gasket) so I figure its time to just replace the motor. I would like 400 foot pounds of tq and am on a budget of about ~$3500. I am going to install her myself adn plan to re-use the vortec intake and replace/upgrade the spider. Any suggestions and links would be appreciated.

I have a 2000 Hoe Limited (5.7 Vortec) and everything is stock except the radio.

Thanks

GM crate HT 383

http://www.gmhorsepower.com/HT-383.php

thats out of my price range....its $4500

U get what you pay dude.hehehhee "bryan "

I agree, but from what I have read on the 383 I would need to replace my entire exhaust and change the RR's an intake to get over the 400 fptq...without those mods I have read to expect 380 fptq. The price for the gain of 10 fptq over the stock motor just seems over priced. Am I missing something when comparing the Vortec 5700 and the 383?

alot more cubic inches and low end torque. Exhaust will be the same, the 350 and 383 extrernally are identical.

Just search for a 383 longblock, use all external's.

I read the stock exhaust chokes it out so you have to go to a 2 1/2 inch exhaust to get the power and tq. I will do a search on her to see if I can find it cheaper. I like the numbers but hate the price....especially since I only need the extra power once a year. How bad is the mpg on her? My 5.7 got 18mpg highway. (8mph when towing)

will be worse. yes, for any real power, dual 2.5" pipe is good, or a good flowing single 3" will be fine.
Gas mileage will vary on cam, compression, gears, driving habits.
But a fresh 355 may be better than doing the 383.

or a long block and a blower...

I have 3 Mustangs and all are NA, so if I buy a blower you know where thats going to go! LOL Around town I drive the Hoe like I am driving Miss Daisey, the Stangs are the ones that get beat on.

Any specs that I should look for on a 355? Also any suggestions on good companies to look at for motors?

thanks for the help.