: Has anyone here built up a 91 Chevy 350?



Wheelman322
01-18-08, 08:38 PM
I read some of the other threads, but I would like to know if anybody has followed through with a Cadillac/Chevy non-LT1 350 build up. I'd like to beef up my 91's 350 and was wondering where I should start.

N0DIH
01-20-08, 05:53 PM
Me?

Go find a set of Vortec 350 heads from 96-up. They are NEW $400-$500. NEW. From GM dealers nationwide.
Get an aftermarket intake that can support your TBI unit and bolt to a Vortec head. Rumors are you can mod a regular intake, but honestly easier to go with a Vortec intake for a TBI. Edelbrock makes one IIRC.
Get a mild LT1 B/D cam if you want torque to move mountains like towing and such or are keeping the lethargic 2.56's to 2.73's or so so 2.93 -3.08 gears. If you are going up to 3.42's or shorter, get at LEAST a LT1 F/Y body cam. These are emissions friendly.

Want more power? I recommend a LT4 stock cam (not HOT cam), or a ZZ3/ZZ4 cam. ZZ3/ZZ4 cams were solid 350 hp cams with heads that flowed like Vortecs.

Top off with some good ECM tuning and a good dual exhaust, prefer with headers for best power and you are easy in the low 14's or high 13's with 3.42's and 4000 lbs with any of the above combo variants.

Easy to make budget friendly power and emissions friendly and be mid 14's with 4000 #'s. Probably can do it all for under $1000 if you shop around well, aren't afraid of used parts, and don't need a rebuild to start with. Just don't do it with a tired engine to start with.... It won't last.

The key, and if you follow the LS1 circles, is airflow. Small cams with good airflow are great drivers. The Vortec heads were patterned after the LT1 heads and flow WELL. And as Elias can attest, stock puny 191/196 duration B/D body iron head LT1's with mods can make 13 second 4500 # cars...

Wheelman322
01-25-08, 01:04 AM
Me?

Go find a set of Vortec 350 heads from 96-up. They are NEW $400-$500. NEW. From GM dealers nationwide.
Get an aftermarket intake that can support your TBI unit and bolt to a Vortec head. Rumors are you can mod a regular intake, but honestly easier to go with a Vortec intake for a TBI. Edelbrock makes one IIRC.
Get a mild LT1 B/D cam if you want torque to move mountains like towing and such or are keeping the lethargic 2.56's to 2.73's or so so 2.93 -3.08 gears. If you are going up to 3.42's or shorter, get at LEAST a LT1 F/Y body cam. These are emissions friendly.

Want more power? I recommend a LT4 stock cam (not HOT cam), or a ZZ3/ZZ4 cam. ZZ3/ZZ4 cams were solid 350 hp cams with heads that flowed like Vortecs.

Top off with some good ECM tuning and a good dual exhaust, prefer with headers for best power and you are easy in the low 14's or high 13's with 3.42's and 4000 lbs with any of the above combo variants.

Easy to make budget friendly power and emissions friendly and be mid 14's with 4000 #'s. Probably can do it all for under $1000 if you shop around well, aren't afraid of used parts, and don't need a rebuild to start with. Just don't do it with a tired engine to start with.... It won't last.

The key, and if you follow the LS1 circles, is airflow. Small cams with good airflow are great drivers. The Vortec heads were patterned after the LT1 heads and flow WELL. And as Elias can attest, stock puny 191/196 duration B/D body iron head LT1's with mods can make 13 second 4500 # cars...

Awesome ideas. So to sum it up....
96 and up Vortec Heads http://cgi.ebay.com/ebaymotors/NEW-350-CHEVY-CHEVROLET-VORTEC-CYLINDER-HEADS-96-00_W0QQitemZ260203907074QQcmdZViewItem?hash=item26 0203907074
Vortec Compatable Edelbrock Intake http://cgi.ebay.com/ebaymotors/Edelbrock-2716-SBC-Performer-EPS-Manifold-Vortec-Heads_W0QQitemZ110215518827QQcmdZViewItem?hash=ite m110215518827
ZZ4 Cam http://cgi.ebay.com/ebaymotors/New-GM-355-horse-ZZ4-S-B-Chevy-billet-steel-roller-cam_W0QQitemZ270205518172QQcmdZViewItem?hash=item2 70205518172
Maybe some 3:08's...Maybe an Impala SS rear or something.
And I'm good for low-mid 14's?

N0DIH
01-25-08, 02:52 AM
Make me an offer, I have an 9C1 rear end (complete end to end), which is the HD Impala rear end with silver calipers....

Yes, that should be fairly easy low 14's, possibly high 13's if you can get traction. You will need ECM tuning for it.

You might very likley find that you hit a wall on quarter mile times, and often the super tight 1400 stall converter is likley the culprit. The S10 converter is a good choice, excellent on cost, but not always the "best" converter. You don't wanna go to nutty on the stall, but a 2100-2200 stall would be helpful....

Putting good money into the heads is very wise $$. Look at the LS1's, the key to the killer power the make is the heads. Look at the cam specs and how much power they are making.... The Vortec heads are the ultimate "best bang for the buck" and gets rid of the anemic L05 choke port heads....(aka, Swirl Ports)

The L31 Vortecs are awesome.... They flow like an LT1 and bolt on just about any Gen I Small Block....

Wheelman322
01-25-08, 10:36 AM
Make me an offer, I have an 9C1 rear end (complete end to end), which is the HD Impala rear end with silver calipers....

Yes, that should be fairly easy low 14's, possibly high 13's if you can get traction. You will need ECM tuning for it.

You might very likley find that you hit a wall on quarter mile times, and often the super tight 1400 stall converter is likley the culprit. The S10 converter is a good choice, excellent on cost, but not always the "best" converter. You don't wanna go to nutty on the stall, but a 2100-2200 stall would be helpful....

Putting good money into the heads is very wise $$. Look at the LS1's, the key to the killer power the make is the heads. Look at the cam specs and how much power they are making.... The Vortec heads are the ultimate "best bang for the buck" and gets rid of the anemic L05 choke port heads....(aka, Swirl Ports)

The L31 Vortecs are awesome.... They flow like an LT1 and bolt on just about any Gen I Small Block....

Thanks again. I can always count on your knowledge to get my project started. How much do you think it would cost to ship a rear from Ohio to New Jersey. Will I have any issues with the ABS exchange? My rear is currently setup with drums. What else will I need to make it work?

N0DIH
01-25-08, 10:42 AM
The axle is a bolt in, you'll need 9C1/Impala e-brake cables,
There is a mod to improve braking, but GM didn't do it, so not NEEDED, but helpful....

Check your sensor, if it is the same one, it is in the diff housing near the driveshaft/pinion.

Have to check on shipping or a way to get it there.

Wheelman322
01-25-08, 05:17 PM
The axle is a bolt in, you'll need 9C1/Impala e-brake cables,
There is a mod to improve braking, but GM didn't do it, so not NEEDED, but helpful....

Check your sensor, if it is the same one, it is in the diff housing near the driveshaft/pinion.

Have to check on shipping or a way to get it there.

Thanks again. I'll check and get back to you.
Would you reccommend a hot head like the 99-up Vortec heads part number 12367712? Would aluminum heads have a negative effect on performance, fuel economy etc...?

N0DIH
01-25-08, 11:59 PM
aluminum heads need around a half point MORE compression to keep the efficiency of the combustion the same (thermal properties require this).

There IS a weight savings with AL over FE heads, but the cost is significant, and it is tough to get a head that is similar cost to the iron Vortec head to beat them. Cost vs weight vs performance.... 'Weigh' them carefully....

96-02 Vortec heads are rumored to all be the same. Some documentation lists another version with thick valve seats and poorer flow, but other reports seem to indicate it flows the same.

caddeville89
05-24-08, 11:31 AM
Ok, so 96-00 Vortec heads @ $400 new, right? Somebody in the other post "Cost of 5.7 Rebuild" mentioned using seasoned heads. I guess the trade-off being that you have to find a car that has them? I am basically looking to do the same with my 90 (the other post is mine), but right now I have NOOO money, so hopefully my motor will go long enough until I can afford that. Though now I'm thinking of buying another car, then working on the caddy myself. I am wondering if I should just buy another 90 with no rust but maybe banged up or dead and transfer everything over from mine (motor, body panels, int. etc...). Mine doesn't have too much rust, but why put lots of money into it if it is going to rot out in 10-15 years??? Will see....lots of other things to pay for in the meantime. :want:

VortecCaddy
09-13-08, 03:44 PM
How did the build go? I was looking through some posts and came across this.

Also, Nodih, do you still have that rear from the SS?

N0DIH
09-13-08, 08:35 PM
Yup, still have it, 3.08's open, with the discs.

A friend of mine was talking about it, but his plans are in flux at the moment....

VortecCaddy
09-14-08, 01:48 PM
It is good to hear that you still have that rear. I do have a question, will that rear be a direct bolt on for a 1990 brougham? I have been searching online and some say that the Impala SS rear is about 4 inches wider than a stock 1990 Brougham rear.

Also, what are you selling it for?

N0DIH
09-14-08, 02:30 PM
Yup, direct bolt in (note this is a 8.5", so if you have a 7.5" axle you might need the 8.5" driveshaft). There is a lot of confusing info on the axle widths. It is wider/narrower due to thickness of the rotor hat, actually not large difference in axle widths. The WAGON axle IS much wider, and cannot be used. This is a car axle.

Do the 90 cars have ABS? This has the 3 channel ABS sensor in there, if needed....