350 sbc 383 sbc, 1980 malibu?

Grumpy

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
Hey everyone, I'm about to build a 350 for my 1980 Malibu. But I'm not sure what is going to be the best setup. need some advice and suggestions. I'm planning to run a stock bottom end, I have vortec heads, some work already done, screw in studs, guide plates, 540 springs, 1.5 narrow roller rockers, 7.8 hardened push rods. rpm edlebrock intake, 750 ec edlebrock carb. Now heres where I'm starting to question things, I have a 8.5 10 bolt posi grand national rear end, just had it rebuilt with 3.73's took out 4.56 to tall. I have a 700r4 aswell I'm looking to be able to cruise and race this thing. So heres my questions, will the 4 speed be the ideal tranny for this setup? Or maybe the th350 is better? Should I change the pistons and go with something of a higher compression, I'm figuring a pretty decent sized cam. id like 400hp out this thing once I'm done. Ive gone all new suspension, poly bushings. New brakes, front to back the only thing not making this a frame off is me not pulling the body off it. Any help and suggestions is much appreciated. Thanks
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one very positive step youve taken, is simply asking those questions before diving off the dock financially with an open check book, without a well documented plan!
the car looks like it has a good deal of potential, and it looks like youve done quality work so far! CONGRATS on a good start!

have you weighted the car at any time in the past when it was running?
the reason I ask right off is you'll want to maximize the power to weight ratio,if you want too build a fast car, and its like beating a dead horse if your dealing with a heavy car and limited resources.

if the cars now a th350/350 v8 and currently has those votech heads, you might want to consider upgrading to a 383 stroker assembly as its a reasonably priced option, compared to the combined cost of, swapping to a manual transmission and new higher compression pistons in a 350.
with that 3.73:1 rear gear ratio and a 3200 stall speed converter either a 350 or a 383 could be built that should run well, but any 383 will always potentially have about a 45 ft lbs and 45 hp advantage due to the increased displacement.

your vortec head will even after port work limit the engines effective breathing or rpm potential,
they are decent heads compared to most cast iron options but keep in mind that your not going to be making power past about 6000 rpm
Id suggest you, stop, and do some research, look at your budget and skills realistically and start by reading a great deal before you proceed, it may not be what you want too hear, but it will save you hundreds of dollars and weeks of wasted effort and financial mistakes selecting the wrong components.


Id suggest you read these threads and sub links,
put some serious thought into both your budget;
and what you would like to drive once the cars rebuilt.
take notes and ask questions.
(read carefully , lots of engine builds will have various changes you might not notice, never assum and yes theres several G.M. vortec heads 170cc, (stock) 225CC (performance) and 185cc aftermarket, etc.

http://garage.grumpysperformance.com/index.php?threads/matching-parts-and-a-logical-plan.7722/

http://garage.grumpysperformance.co...y-in-building-a-good-engine.11682/#post-54682

http://garage.grumpysperformance.co...ch-quest-series-similar-350-383-sbc-info.519/

http://garage.grumpysperformance.com/index.php?threads/compression-question-383.12861/

http://garage.grumpysperformance.co...k-for-in-a-good-engine-combo.9930/#post-46399

http://garage.grumpysperformance.com/index.php?threads/another-383-build.12786/

http://garage.grumpysperformance.com/index.php?threads/my-1st-street-383-build.6962/

http://garage.grumpysperformance.com/index.php?threads/383-information-overload.11137/

http://garage.grumpysperformance.com/index.php?threads/383-combo-newly-bulit-up.4120/

http://garage.grumpysperformance.co...g-with-a-local-machine-shop.14419/#post-74383

http://garage.grumpysperformance.com/index.php?threads/finding-a-machine-shop.321/#post-59253

http://garage.grumpysperformance.com/index.php?threads/hows-this-383-combo.5517/

http://garage.grumpysperformance.com/index.php?threads/383-build.2645/

http://garage.grumpysperformance.com/index.php?threads/think-thru-your-goals.10606/#post-73288

http://garage.grumpysperformance.com/index.php?threads/the-new-215cc-vortec-heads.266/#post-75012

http://garage.grumpysperformance.co...-vortec-heads-and-other-heads.401/#post-34996

http://garage.grumpysperformance.com/index.php?threads/vortec-info.529/#post-27299

http://www.hotrod.com/articles/1206phr-383ci-small-block-chevy/

http://www.superchevy.com/how-to/76178-chevrolet-ht-383-engine/

http://www.enginelabs.com/news/dyno-video-qmp-builds-500-horse-383-stroker/

http://www.chevyhardcore.com/tech-stories/engine/building-the-little-383-small-block-that-could/

http://royalpurpleconsumer.com/wp-c...-block-in-six-easy-steps-hot-rod-magazine.pdf
 
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Indycars

Indycars

Administrator
Staff member
At somewhere around 400 HP, they 700r4 would be a good option. He wants to cruise and
race, the OD will allow this. He already has the trans and would not be too expensive to build
and meet the 400 HP objective.
 
Maniacmechanic1

Maniacmechanic1

solid fixture here in the forum
His New 4.56 Gearset is in the Buick Grand National 8.5 rearend.

700R4 has a 3.06 :1 1st gear.
The 1-2 shift is like 43 % rpm drop I recall.

TH400 Trans is like A Muncie M20, M21, M22 Close Ratio Perfection in an Automatic Trans.

700R4 is a Perfect match with 2.73 gears like in my Corvette.
Tpi gives it a wide powerband off idle.
John experienced the same with his all steel Chevelle with a 700R4 and 2.56 rear diff gears.
Made to pull a tall gear a 700R4.
 
Strictly Attitude

Strictly Attitude

solid fixture here in the forum
Yes that is why 1st gear is so low on 700r4 ne pulled the 4.56 and put in 3.73 though had to reread Brian 700r4 good option if you have one or but allot of other trans options to invest in
 
Mark Bradley

Mark Bradley

Da guy in Newbury
350 or 383?
400hp is much easier when your starting with 33 more cubic inches.
As for manual trans or automatic.
A Muncie is good for about 400-450 hp before you need to throw a shit load of money at it. If your a manual trans person then go for a Tremec and live a happy life.
On the flip of that..crushing in traffic is much better in an automatic and unless your a pro your not going to shift an manual faster than an auto.
 
Maniacmechanic1

Maniacmechanic1

solid fixture here in the forum
Mark Bradley said:
350 or 383?
400hp is much easier when your starting with 33 more cubic inches.
As for manual trans or automatic.
A Muncie is good for about 400-450 hp before you need to throw a shit load of money at it. If your a manual trans person then go for a Tremec and live a happy life.
On the flip of that..crushing in traffic is much better in an automatic and unless your a pro your not going to shift an manual faster than an auto.
Click to expand...
There is only one guy around from the past Corvette drag racing world that knows how to build a T56 or Tremec and not have it hang up in gear on the 2-3 & 3-4 WOT Upshift at 6500-7000 rpms.
Hardcore.
I have not spoke to him in a long time.
Doing his own thing On Facebook.

Tremec is fine till you try and drag race.
 
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