Anybody tried the 91-93 HT 502 retrofit kit?

[retromek]

Looking for feedback from people that have done the swap. Is it worth the trouble?
Does it kick butt or does chiraco grade.
Towing 7000lbs.

[RaysonRat]

how can you go wrong with 312hp and 612ft pounds of deisel killing torquw, i love mine in my 97 suburban plus it really didnt hurt the milage and who can argue with a suburban that will do full on muscle car burnouts through like two gears yeah baby

[victorfb]

i have a 91 GMC duelly that i did the 502 retro fit kit on. i also did the edelbrock multipoint injection system, edelbrock headers, and such. it tows a 38' fifth wheel toy hauler, and the 502 definatly out performed the 454, and possibly even gained fuel mileage. no numbers to confirm it, it just seemed to by the comparison between fill ups. with only a 7000 pound trailer i would think you will really see a big diferance. if you decide to do it, do your research. the price of the entire package difers dramatically from one dealer to the next. shop around.

[565edge]

I would buy some edelbrock smog legal heads and put a whipple on it.I built a 383 stroker with a whipple for my 94 1/2 ton and its unreal.The whipple is the only way to go.

[SPECTRABRENT]

Victor,
What dealer did your conversion?
I am thinking about the 502 on my Suburban.
Brent
[ October 04, 2003, 09:42 PM: Message edited by: SPECTRABRENT ]

[Dr. Eagle]

I am just curious, how did you get away with it? What I mean is it used to be that when you bought a vehicle you were not allowed by the state to change the powerplant from it's smog certified configuration. They have come up with smog certified aftermarket stuff, which were rare in in the 80s and early 90s, but a quantum upgrade to a 502 cu in engine? Is it a kit that GM got smog certified?

[victorfb]

i did the conversion myself. the kit was purchased through paradise chevrolet in temecula, but i had to show them a bunch of print outs from other dealers. i think vegas was the cheapest at the time and they matched it.
the retro kit is just that, a replacement motor for the 1990-1993 454. it has an executive order that makes it smog legal. but the motor is detuned to recieve the cert. with a bigger cam and more cam timing that thing would haul ars. but lose the smog legal acceptance. the kit is pretty nice actually with the duel exhaust, duel high flow cats and mufflers, trans cooler, trans shift plate valve body, wiring harness, computer chip, fuel pump,and a few other goodies.

[SPECTRABRENT]

Did you have to do any major mods to the trans?
Brent

[Dr. Eagle]

That is cool, the 502 has quite a bit more torque than the 454. I imagine that you have to have the big block in the first place to be legal to upgrade???

[victorfb]

yes it is true the conversion is for 454 replacement only. the trans was also replaced at the time of engine swap. the kit came with a new trans plate that is easy to install, but i actually had my tranny guy do it while doing the replacement. there was also a new wiring harnes but i had allready upgraded that before hand so now i have an extra. the wiring harnes was to fix an existing problem with the factory GM tranny's.
the kit comes with a pretty decent step by step instruction booklet and to be honest, it was pretty simple.

[565edge]

Even the factory 454 were detuned for for emissions when they were at the factory.My buddy had a 1993 crew cab dually that was a turd after 1/2 throttle,It pulled great but after 1/2 throttle it wouldnt do any more.Lack of timing and fuel.When i did my 1/2 ton truck i had to have a custom e-prom made for it,They had the truck for 2 weeks but it was night and day difference.When we picked it up we were talking to him about the 1 tons and he started laughing and knew what the problem was.He has a custom tuned chip for these trucks that make them run night and day difference and still pass smog.Basically the dead spot from 1/2 to full throttle was gone.His dually ripped after this.With the money spent on a 502 though i would whipple charge the 454 and put a nice set of heads on it then have a custom chip made.