4.3 questions

Jay127 · **Posted:** Mon Dec 03, 2012 11:00 am

So I just got the motor out to replace the flywheel and I decided to replace he heads with actual vortec heads and I'm ordering a 4 barrel intake to go on the new setup since my old intake will not work. Originally it had a 2 barrel. Will I notice the power difference with this setup? Is there anything else that Would benefit this motor. Also any idea if ill have to reprop? Thanks

Oh sorry
1995 Fourwins Sumdowner 20' 4.3 V6

ric · **Posted:** Mon Dec 03, 2012 11:24 am

Jay127 wrote:

So I just got the motor out to replace the flywheel and I decided to replace he heads with actual vortec heads and I'm ordering a 4 barrel intake to go on the new setup since my old intake will not work. Originally it had a 2 barrel. Will I notice the power difference with this setup? Is there anything else that Would benefit this motor. Also any idea if ill have to reprop? Thanks

Oh sorry
1995 Fourwins Sumdowner 20' 4.3 V6

Well, the true vortec setup is a roller camshaft. Your non-vortec engine is a regular hyd flat tappet design. Part of why the vortec engine has 220hp is the roller camshaft with a better profile. If you use your non-vortec camshaft setup with vortec heads and 4bbl there's a good chance you'll run into running issues.

If you install the vortec heads, vortec roller camshaft setup, edelbrock intake, holley 4bbl vacuum secondary carb you'll be right at around 220-230hp. That's over 60hp more then stock what it's currently making. Yes you will notice the power difference.

Jay127 · **Posted:** Mon Dec 03, 2012 12:31 pm

Thanks I knew I'd be replacing that forgot to mention it in post.

Jay127 · **Posted:** Mon Dec 03, 2012 1:49 pm

Any recommendation on cam or just the stock roller cam. Also where mine is the 95 vortex is there any chance that it already has the roller calm

ric · **Posted:** Mon Dec 03, 2012 2:26 pm

Jay127 wrote:

Any recommendation on cam or just the stock roller cam. Also where mine is the 95 vortex is there any chance that it already has the roller calm

There's vortec 4.3 and there's not. There's no internal variants in any year in any application (boat, car, truck). If your original engine has the 8 bolt intake it's a vortec 4.3 and has the good heads and roller cam. If it has the 12 bolt intake it's not vortec and it has the standard cam.

You have a 195 Sundowner so you could easily go with an upgraded cam. I was going to do the edelbrock performer cam/intake on my 4.3.

Jay127 · **Posted:** Mon Dec 03, 2012 5:00 pm

Ric I read the the 95 vortecs differed from the 96 and newer. That's why there only like 160 hp. So even though its labeled vortec it's not the real thing. Right?

ric · **Posted:** Mon Dec 03, 2012 5:41 pm

Jay127 wrote:

Ric I read the the 95 vortecs differed from the 96 and newer. That's why there only like 160 hp. So even though its labeled vortec it's not the real thing. Right?

Here's the confusing part. The 4.3 was always called "Vortec", that was it's brand name since 1985. In 1996 GM released the new fast burn head design and to save money/lazy/whatever, called the new heads "Vortec" and branded all engines with those heads Vortec (Vortec 4300, Vortec 5700, etc).

Today when someone says something is a Vortec engine they mean the fast burn head design for the 4.3/5.7/whatever. Ignore the fact your engine has Vortec on it, it's a standard 4.3 as designed in 1985 and is what is called a "pre-vortec" 4.3.

Jay127 · **Posted:** Tue Dec 18, 2012 11:31 am

if i go with edlebrock carb and intake am i going to run into any issues with hooking up the throttle linkage

ric · **Posted:** Tue Dec 18, 2012 12:30 pm

Jay127 wrote:

if i go with edlebrock carb and intake am i going to run into any issues with hooking up the throttle linkage

Edelbrocks suck on boats, their secondaries are mechanical. You want vacuum secondaries on a boat. You'll get bad fuel consumption and hesitation.

Jay127 · **Posted:** Tue Dec 18, 2012 12:32 pm

so what would be the best choice for the boat.

Jay127 · **Posted:** Wed Feb 13, 2013 12:13 pm

I just got back from the builder and we noticed something interesting. The motor was a true vortec lower end. It was balanced and had the roller cam. We are guessing that in the past they replaced the block. this is the info from the block. s/n t1282554 model 432aphub. any info on this would be great.

john55c · **Posted:** Thu Feb 14, 2013 6:43 pm

Jay127 wrote:

I just got back from the builder and we noticed something interesting. The motor was a true vortec lower end. It was balanced and had the roller cam. We are guessing that in the past they replaced the block. this is the info from the block. s/n t1282554 model 432aphub. any info on this would be great.

Search Google for Chevy block casting number and you will be able to search and find the info with specs.

ric · **Posted:** Thu Feb 14, 2013 10:59 pm

Vortec is vortec, non is non. Doesn't really matter where it came from they're all the same.

Jay127 · **Posted:** Fri Feb 15, 2013 12:11 pm

ric wrote:

Vortec is vortec, non is non. Doesn't really matter where it came from they're all the same.

i understand that but the motor has non vortec heads cause its a 95. But there is a roller cam and its a balanced motor. So wouldnt that mean the botom end is from a 96 and newer vortec. Not just the 95 where they labeled it vortec but its not really one.

www.iFourWinns.com

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