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Chevy 4.3 V6 w/Vortec Heads Questions -Swap into a Pontiac T1000 (Chevette)

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6.1K views 20 replies 11 participants last post by  skinny chicken  
#1 ·
My son just picked-up a 1993 4.3 V6 to swap into his 1982 T1000. I never owned a 4.3 V6 and do not have any experience with them.

He is going to have the short block rebuilt, but wants to upgrade to a set of later Vortec heads. He wants to run a Comp Cams 270 or 280 HR Cam. It will be backed by a manual, a V8 Camaro T5 if he can find one. He'll be running a Edelbrock carb'd intake and a 500 CFM Edelbrock carb for now. Car has a 4.10 posi rear end.

1. Do the V6 vortec heads have the same valve lift limitations as V8 Vortec heads @ +/- .450" max lift?
2. Are the LS6 valve springs a direct drop in on the stock Vortec heads?
3. Is the 280 Cam too big for a daily driver?

270 HR COMP Cams 18-420-8 Magnum Hyd. Roller Camshaft, Chevy 4.3 V6

280 HR Cam

Possible valve spring Kit if LS6 springs won't work
Valve Spring Kit, SB Chevy VORTEC, HI-Perf Hyd Roller, 130 Lbs Seat Pressure, VSK4H53

Thanks in advance
116065
 
#3 ·
My son just picked-up a 1993 4.3 V6 to swap into his 1982 T1000. I never owned a 4.3 V6 and do not have any experience with them.

He is going to have the short block rebuilt, but wants to upgrade to a set of later Vortec heads. He wants to run a Comp Cams 270 or 280 HR Cam. It will be backed by a manual, a V8 Camaro T5 if he can find one. He'll be running a Edelbrock carb'd intake and a 500 CFM Edelbrock carb for now. Car has a 4.10 posi rear end.

1. Do the V6 vortec heads have the same valve lift limitations as V8 Vortec heads @ +/- .450" max lift?
2. Are the LS6 valve springs a direct drop in on the stock Vortec heads?
3. Is the 280 Cam too big for a daily driver?

270 HR COMP Cams 18-420-8 Magnum Hyd. Roller Camshaft, Chevy 4.3 V6

280 HR Cam

Possible valve spring Kit if LS6 springs won't work
Valve Spring Kit, SB Chevy VORTEC, HI-Perf Hyd Roller, 130 Lbs Seat Pressure, VSK4H53

Thanks in advance View attachment 116065
Cool car! But good lord, I don’t know how you put up with that fart can!!
 
#6 ·
I have been told they have the same spring limits and need the same work as a v8 head. there is a video on a cam swap and rebuild of one out there. holder did a bunch of stuff to 1 or 2.
I was watching some of Richard Holdener's videos this evening. The guy does some cool stuff. He likes the 280HR cam over the 270, but my gut tells me to go smaller on the cam.

From searching the web tonight, it seems like the heads will need the same upgrade as the V8 vortecs. I'd like to use LS6 springs if they're a direct drop in. It also looks like he can use a flat top piston from a 350. If he's willing to go automatic, I have a nice 700R4 and 2800 stall FTI converter he can use. I have an ECP radiator for a 57 Chevy that looks like it will fit. I think for accessories he will go with a SWP set-up from a SBC, with a 62-67 Nova low mount alternator kit, or a 69-72 C10 set-up if the alt bracket will bolt to the driver side head and work with a swp. We can test that once he finds a pair of V6 vortec heads, which shouldn't be too hard to come up with, unlike a V8 Camaro T5....
 
#8 ·
Killer project! I had an 82 Chevette and man I miss that car. So fun to drive. FWIW if the 4.3 heads use the same self aligning rockers then I highly recommend having guide plates and screw in studs installed. I did that on my vortecs and run a regular rocker arm. I also milled the guide bosses milled and I'm running a .530 lift cam. If I can find my cutter then you are welcome to use it on your heads. It's used with a drill and has an alignment rod to center the cutter. Got it from Eastwoods.
 
#12 ·
Thanks for the offer, I have a tool from comp cams for the guides, and another to drill the push rod holes for the 1.6 rockers. We'll probably have the machine shop convert to screw in studs and guide plates.
 
#13 ·
It should make for a nice driver. He was contemplating a later GM turbo 4 swap, but the cost lead him to the 4.3. I daily drove a 19890 Monza Notchback, 4 cyl 4spd for years, but always wanted a vega or chevette. I may pick one up with the goal of trying to build one with a goal of high MPG vs performance to be my daily. Would like to get 35+. I think it was PHR that got 30 mpg out of a Monte Carlo in the late 80s/early 90s, so 35 mpg ought to be doable now adays.