.. LOL! Only took 5 pages of arguing, but you guys finally more or less got to Step #1: get the truck, take it out on a closed top end course, and see what it'll do... then you know exactly what it's lacking... make a good guesstimate of what it would take to reach around 128 MPH from there... can that be done with home-modded stock or newer Vortec V6 parts... or would it take out-of-budget unobtanium parts? Or, dare I say it, a budget V8? Headers plus fixing the crappy quench and compression ratio and casting irregularities on these engines can go a long way toward obtaining the RW power these V6 and V8 engines of that era should have made from the factory... once that's fixed, then they are able to take advantage of a cam bump up as well, if needed... is that enough?
.. Chad/OP mentioned 128 MPH goal... also mentioned at least over 115 MPH... apparently he's using top speed as a 'poorman's dyno'... and that works... if it makes his goal, it's gonna rock pretty good 0 - 70 against his friends... nitrous costs around $60/minute to operate, so kinda limits a lot of fun... and, of course, takes even more nitrous to move a truck very far... and you won't get very far in a boat on nitrous ( I boat on 250 mile long x 55 mile wide Lake Erie )... if some braggart says his S-10 has 500Hp and it actually peters out at 97 MPH on the 'top speed dyno', well, that's that... the cat's out of the bag on him...
.. Chad said right off his friends have trucks, so no need to compare his truck to cars of any sort...
.. Somebody mentioned it costs $5,000 to get 350HP out of a Chevy 350... reminded me of this $1,000 410+HP 440lb.-ft. torque build (OK, prolly a slightly happy dyno, but still...):
Low Budget Chevy 350 Small Block Engine Build - Classic Trucks Magazine
.. Anyway, this brings us to plans. The object of Chad's first posting. What RPM did the truck max speed at stock? In what tranny gear? What's the rear gear (3.73) and tire size? To get to 128 MPH you need gearing that allows the engine to reach peak HP RPM at, say, about 126 MPH so it can get up their quicker... then it'll still rev a bit more with power for that last couple MPH... What RPM is the newly modified engine likely to HP peak at? (Lots of the guys here can give you a pretty close estimate!) Does the computer need an RPM limit removed or raised in it's software? From there, we plug all the info into the online calculator and check the resulting spreadsheet to see if something needs to be changed (tire size, rear gear):
(hit 'clear right' button before doing anything)
.. ( 700-R4 tranny gears can be entered automatically by selecting " F-Body A-4 " from the dropdown menu at the top, you'll have to correct rear gear ratio if one pops up, I usually enter 6500 RPMs redline for a street vehicle)