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Joined: Dec 2014
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HEI "in the 70's" used centrifugal and vacuum advance....tunable.
Later HEI's had the ECM tuning the advance, so also tunable for those w/the right tools. Soooo HEI isn't a detriment to engines w/low RPM tq.
The timing curve is not specific to, or because of the fact that it's "HEI"...it's tuned in, just like any distributor, or any electronically controlled EFI system.
HEI's may "fall off at high RPM", but 4000 isn't what we call "high RPM" and it's certainly not any where near where a stock HEI will start to have any issues. When an HEI does begin to fail (due to high RPM) it's the coil -easily replaceable. Anyway, HEI's in proper working order are way better than good enough for most 383 builds that are done on this or any forums.
Reading comprehension is not typically an issue for me, and it wasn't here either. The limiting factor on the 383 you have was due to the stock, un-ported intake...not the HEI -as you implied.
Later HEI's had the ECM tuning the advance, so also tunable for those w/the right tools. Soooo HEI isn't a detriment to engines w/low RPM tq.
The timing curve is not specific to, or because of the fact that it's "HEI"...it's tuned in, just like any distributor, or any electronically controlled EFI system.
HEI's may "fall off at high RPM", but 4000 isn't what we call "high RPM" and it's certainly not any where near where a stock HEI will start to have any issues. When an HEI does begin to fail (due to high RPM) it's the coil -easily replaceable. Anyway, HEI's in proper working order are way better than good enough for most 383 builds that are done on this or any forums.
Reading comprehension is not typically an issue for me, and it wasn't here either. The limiting factor on the 383 you have was due to the stock, un-ported intake...not the HEI -as you implied.
FWIW, I bought another complete CFI system off eBay... I wanted the cleaner cover anyway to replace mine which has some cosmetic issues and it was just as cheap to buy a complete one as just the cover... And a whole lot cheaper than a Renegade...
Soo... Now I think instead of buying a Renegade intake I may try my hand at porting out this other one. I may also try boring out the throttle bodies to 2". I know where I can get 2" throttle vanes and 90lb/hr injectors from a 7.4L TBI and it doesn't look hard to swap the injectors or throttle vanes. All I need to do is find where to get the steel bushings for the shaft.
All this may not even end up costing as much as I thought it would. I love a DIY project, although I am often a little slow in getting them done...
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
Soo... Now I think instead of buying a Renegade intake I may try my hand at porting out this other one. I may also try boring out the throttle bodies to 2". I know where I can get 2" throttle vanes and 90lb/hr injectors from a 7.4L TBI and it doesn't look hard to swap the injectors or throttle vanes. All I need to do is find where to get the steel bushings for the shaft.
All this may not even end up costing as much as I thought it would. I love a DIY project, although I am often a little slow in getting them done...
All this may not even end up costing as much as I thought it would. I love a DIY project, although I am often a little slow in getting them done...
I don't know if you'll need the 90 pph injectors for a mild 350. I've seen and I myself have run ~250 horse 350's w/CFI on the stock injectors just fine. When I moved to a 400 sbc, (~300 hp) then I definitely needed the bigger injectors and more fuel pump.
TB boring won't help power at all on a stock or stockish engine. What it will do is increase throttle response, or the "touchiness" of the throttle at low angels. Proceed at your own discretion there.
Burning Brakes
Joined: Feb 2013
Posts: 1,173
Likes: 152
From: norway
yes porting is the "fun"way to go pics of my porting jobb under my profile ! more fun making stuff than just go by stuff 
http://www.ebay.com/itm/Carbide-Burr-SC-3NF-6-Cylindrical-Ball-Nose-Aluminum-Cut-1-4-x-3-8-x-3-4-x-/161402543701?pt=LH_DefaultDomain_0&hash=item2594575e55 http://www.digitalcorvettes.com/foru...d.php?t=101038 http://www.ebay.com/itm/15-16-938-Flex-Hone-Flex-Hone-Brush-Research-Cylinder-Hone-180-grit-24mm-/231520949595?hash=item35e7b9555b https://www.corvetteforum.com/forums...re-intake.html
pics of my porting jobb under my profile ! more fun making stuff than just go by stuff http://www.ebay.com/itm/Carbide-Burr-SC-3NF-6-Cylindrical-Ball-Nose-Aluminum-Cut-1-4-x-3-8-x-3-4-x-/161402543701?pt=LH_DefaultDomain_0&hash=item2594575e55 http://www.digitalcorvettes.com/foru...d.php?t=101038 http://www.ebay.com/itm/15-16-938-Flex-Hone-Flex-Hone-Brush-Research-Cylinder-Hone-180-grit-24mm-/231520949595?hash=item35e7b9555b https://www.corvetteforum.com/forums...re-intake.html
Last edited by corvettenorway; May 26, 2015 at 11:46 AM.
