Hummer

Has anyone tried the swap of GM '96-'97 L31 Vortech heads on their 305. Any problems with the swap. How about timing, will my engine need less advance? Should I change my intake or can I use the stock one? Any other FI heads work?

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1986 Camaro Z28
White w/ T-tops
Tinted Rear Window
ENGINE
305 H-code
Gasket-matched heads and intake, ported and polished
Comp Cams 224 @.050
.472 lift I/E
Dual Snorkel Air Cleaner w/ K&N filter
Accel 8.8mm wires
TRANNY
700-R4 w/custom built 3000 stall converter
tranny cooler
EXHAUST
Flowtech Headers
No cat
Dynomax muffler
STEREO
Alpine CDA-855
Kenwood 4X6's, 6X9's
MTX 4240 amp
2 Sony 12" X-Plod's
Alpine 8440 alarm
Uniden 6599 Radar Detector

Take 'er easy, and if
she's easy, take 'er twice!!!

BrianF

Well I am in the process of doing the swap I am having .020 milled off the heads, using flat top pistons. You will need to mill about .035 to .045 to get the compression up to a good point. Yes you will need a new intake and stock to hot timing is good.

Need any more let me know.

Brian Felts

Ray87Z

Here's a 305 buildup article where they end up w/ Vortec head on their LG4. It may answer some of the questions you may have. They made some pretty good power w/ nothing radical in the engine at all...

Go to this link for the first page, then manually change the page1.jpg in your browser to page2.jpg etc to view the other pages... 5 or 6 pages total I believe. <a href="http://www.inter-scape.com/ray/305buildup/page1.jpg">LINK HERE</a>

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Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray

[This message has been edited by Ray87Z (edited April 07, 2001).]

Jer82Z28

I put a set of vortecs on my LG4 last summer, I left the heads the way they were and lost a lot of compression, but it was a huge improvement over the stock heads nonetheless.
I left them because I had plans for a 350 swap anyway.

the gap for vortec heads are .065, which is a huge gap, i gaped my plugs to that and found myself needing a whole lot of timing advance and a very rich carb setting. gap your plugs to your normal .035 since the ignition on your car is not the same as the trucks which the heads come off of. your timing and carb shouldn't need too much adjusting that way.

and you will need a vortec specific intake cause of its crazy bolt pattern.

zippy

been done many times even in magazines and they aren't vortech, they are vortec. the years are from 96 and up. still being made for the L31 now.

Hummer

Who`s intake manifold did you use? part #? Like it?

Hummer

^^^^^

Hummer

I'll try again...^^^