The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 01-05-2001, 11:18 AM   #1
Mike - 76 k20
Registered User
 
Join Date: May 2000
Posts: 24
Post ideas for Vortec two-piece rear main block 350

I need some ideas for a 350 rebuild. I'm sold on the cast-iron Vortec heads, so that's decided already. They are 62cc, I've read, and I am looking for a CR around 8.5 so I can run 87 octane.
Is that the highest CR I can run on 87? Gas is so expensive these days, so I don;t want to have to buy booster, 89, 92 (gasp), or have to *aquire* more av-gas.
I'm needing low-end torque, so I'm seeing the Edelbrock 180 degree #7101. I already have a #1406 650 carb.
Next question is - what about a 383? Speed-O-Motive sells a budget 383 kit for pretty cheap. It's a new cast crank, refurb 5.7 rods, and new pistons. I'm not planning on a nitrous bottle or a blower, so cast should be fine.
I'd then have to buy an external balancer and a 400 flywheel, right? Where is a good place to get these? I have a manual tranny.
Also, I have a choice fo two blocks, both two-piece rear main.
One is a 1973 two-bolt. It is already pulled and sitting in the back of my truck, needs to be disassmebled and, of course, to have the machine work done.
The other is a 1980 (or 1979) four bolt, currently in the truck I am driving. It has low oil pressure (I think the bearings are pretty worn) and needs to be pulled in the next year or so anyway because it's on its last legs. The problem with using this engine is that I would then have to install the 2-bolt in its place until I get the 383 built, which is probably going to be many molnths of working on it, a little here, a little there, as money and time makes itself available.
How much of an advantage is a four bolt block? Enough to justify the extra labor (and rental time with a engine hoist) to pluck it and install the 2bolt?

I'm looking at the COmp Cams 286 4x4 cam. I think it would work well with the engine setup.
What about the distributor? I have a 76 HEI, works fine, but I've never run a new one so maybe it is missing a little oomph? Even if I go buy a Summit or MSD new one, what about the advance curve? I've heard of people having a shop tune these, but where do you get it done? I live in Houston and haven;t seen anyone offer this service.
I'm full of questions ain't I?
ANother question - what machine work is mandatory? Obviously hone the bores to whatever the next size is. Deck the block. WHat about align-honing the crank? What else? I plan on this engine running strong for 100K+ miles, so reliability is key.
What about the valvetrain? The Vortec heads come assembled from GM, and the Comp Cams kit comes with new lifters, what else do I need for a complete valve-train?
--Mike

Mike - 76 k20 is offline   Reply With Quote
Old 09-30-2012, 11:13 AM   #2
C-10 simplex
Account Suspended
 
Join Date: Dec 2008
Location: indisclosed
Posts: 1,515
Re: ideas for Vortec two-piece rear main block 350

This is a good question; How low octane can you run with say 9:5 to 1 compresion? How about 10 to 1?
C-10 simplex is offline   Reply With Quote
Old 09-30-2012, 11:35 AM   #3
SSC's76
No No
 
SSC's76's Avatar
 
Join Date: Jun 2005
Location: Pueblo Colorado
Posts: 1,781
its not that you can't run lower octane fuel its a matter of not being able to run enough timing to unlock the power of the engine. there are alot of variables to consider altitude weight base timing and mechanical advance. the 383 in the wifes buick came from my truck where anything lower then 91 would cause it to ping and rattle seems to be just fine in her car with with 85.


Posted from 67-72chevytrucks.com App for Android
__________________
1976 Custom Deluxe SWB Med FMB.3/4 Drop.
Gen VI 454, Muncie HD 3 speed With Modified OE Hurst Shifter, 3.73 12 bolt, GMPP HO roller cam, Hooker headers, Performer intake with modified Q-jet, Accel distributor. Best 1/4 12.3 @108. Funnest run 19.84 @88 full 1/4 mile burn out.
1997 K1500 ext cab 5.7 stock except muffler
SSC's76 is offline   Reply With Quote
Old 09-30-2012, 04:01 PM   #4
INSIDIOUS '86
Registered User
 
INSIDIOUS '86's Avatar
 
Join Date: Jul 2009
Location: washington
Posts: 4,178
Re: ideas for Vortec two-piece rear main block 350

http://www.nastyz28.com/forum/showth...=56505&page=58

All you need to know about vortech in the link

Run the higher compression and better fuel and the gain from power will be worth it
Posted via Mobile Device
__________________
377 sbc thumpr cam autogear m23 muncie 3:73 Detroit trutrac
3''spintech prostreet mufflers xpipe 1 3/4 headers
build thread !http://67-72chevytrucks.com/vboard/s...d.php?t=577217
Iroc gauge threadhttp://67-72chevytrucks.com/vboard/s...d.php?t=554511
INSIDIOUS '86 is offline   Reply With Quote
Old 09-30-2012, 04:59 PM   #5
raceman6135
Dino burner
 
raceman6135's Avatar
 
Join Date: Nov 2002
Location: Calgary, Alberta, Canada
Posts: 602
Re: ideas for Vortec two-piece rear main block 350

Umm.... the OP posted this more than 11 YEARS ago and has not posted since.

Just in case you're wondering why he might not reply
raceman6135 is offline   Reply With Quote
Old 09-30-2012, 05:15 PM   #6
INSIDIOUS '86
Registered User
 
INSIDIOUS '86's Avatar
 
Join Date: Jul 2009
Location: washington
Posts: 4,178
Re: ideas for Vortec two-piece rear main block 350

LOL c10 simplex where how did you find this?
Posted via Mobile Device
__________________
377 sbc thumpr cam autogear m23 muncie 3:73 Detroit trutrac
3''spintech prostreet mufflers xpipe 1 3/4 headers
build thread !http://67-72chevytrucks.com/vboard/s...d.php?t=577217
Iroc gauge threadhttp://67-72chevytrucks.com/vboard/s...d.php?t=554511
INSIDIOUS '86 is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 11:33 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com