Help starting LS transplant

[n8thenetninja]

Hello everyone! I'm starting an LS swap in a '75 Vega hatchback l. I figure I'm probably not the first to attempt this swap, so I thought I would ask you all for tips, part numbers, etc.

Here's my plan so far:
The goal is a 12 second (at 5000ft) street/strip car.
I have an aluminum 5.7l short block and 241 heads. I'm going to install ARP rod bolts and upgraded valve springs and push rods for an aftermarket cam. I have a TH400 transmission that I plan to use also. I'll most likely go with a 9" rearend with a torque arm. Sub frame connectors will be a must I figure, and I will be doing the s10 front suspension upgrade

I have a few main questions, but I'm open to any constructive feedback at this point.

1. What headers have worked in the past? Long tubes or at least mid length 1-3/4" would be ideal. Any off the shelf options?
2. What are the best options for motor mounts?
3. What radiator and transmission cooler works well?
4. What front coil springs work best?
5. About how much will the car weigh all said and done? I'm guessing 2800 lbs or so, since that's what the V8 Monza weighs.
6. Any other helpful information you can think of.

Thanks everyone!

[monzaaddict]

http://www.powerbyace.com/

[EVL VEGA]

http://forums.h-body.org/viewtopic.php?f=20&t=28042

[n8thenetninja]

http://www.powerbyace.com/

Awesome! More bolt-in parts than I ever hoped to find for this swap.

http://forums.h-body.org/viewtopic.php?f=20&t=28042

Good reference material. I'll be sure to make a similar journal when I start making more progress on mine.

[monzaaddict]

If your goal is a 12 second car and you plan to use an ls1 I would use a th350 (actually I wouldn't - I would use a 4l60e or t56 but I am assuming you want to do this within a budget). If your car is a 3 speed automatic from the factory it has a th250 which is an air cooled version of the th350 with fewer friction discs. If you use a torque arm then get a monza tailhousing The th350 will drop right in where as the th400 will require beating the tranny tunnel for clearance and fabricating a tranny mount and torque arm mount. .

I wouldn't waste the money on a 9" ford. Get a 7.5 monza rear from http://jdrace.com/products/products.htm with later model gears using the cut down pinion, aftermarket axles, larger u joint flange and girdle. If converting to a torque arm then use monza parts. It will all bolt in but you will have to fabricate a panhard rod to body mount. Or you could use the upper control arm brackets from your stock rear and keep the 4 link. the brackets will need to be extended upward to eliminate wheel hop. use 76 monza backing plates and all the hardware and s10 etc 5 lug drums.

You can also get an 8.5 rear out of a v6 5speed s10 2wd ( not sure of the years but the info is on this site). weld on your brackets and you are pretty much set. You cannot use a torque arm with this setup - 4 link only!

I would not use the s10 spindles. go with 69 camaro spindles ( also used on chevelles and novas. use the a body steering arms and reverse them so they angle out instead of in. http://www.usmuscle.com.au/Forum/showthread.php?p=50785
You will have a lot more braking options. Modify a set of deep pocket control arms with sway bar mounts to accept the required balljoints. you will also need different brake hose, master cylinder and likely a proportioning valve.

Use the powerbyace.com mounts, pan and headers. I believe the hooker ls manifolds will work with his mounts and cts-v manfolds look like they will work. 98 camaro stamped manfolds also look like they will work but require the egr ports to be welded and the drivers side flange has to be modified to use a standard 3 bolt exhaust collector. I personally would use manifolds and not waste the money on the headers unless you really want headers and don't mind spending the extra $800. His mounts and pan kit I would use. The pan is going to be costly but allows the engine to be installed in the exact location with regard to the crank centerline and bell housing mounting flange as a factory v8 monza. This is going to give you the clearance you need around the steering shaft , centerlink and keep your driveline angles correct.

using the corvette/ctsv water pump is going to give the maximum clearance for an electric fan.
Griffen has a nice bolt in aluminum radiator.

use v6 non ac monza springs with the deep pocket lower control arms.

I wouldn't bother with the subframe connectors either for a 12 second car.

I would keep the fuel injection.

I wrote this a few years back as a repository of ideas for my monza - whenever I get around to building it. this was before the powerbyace mounts, pan, headers were available. Go through the links as more than a few pertain to vegas.
viewtopic.php?f=1&t=33358

[n8thenetninja]

monzaaddict, thanks for the info!

I tend to shy away from the 4l60e because I have one in my LS1 S10 Blazer that I have blown up three times already. That is with a mild LS6 type engine running high 13's. Too much of a money pit for me. I had thought about a T56, but their popularity has driven the price sky high, and drag racing a stick car means everything has to be stronger to keep from breaking things. I thought about doing a 4l80e, but I would have to build a new transmission tunnel. I decided on the TH400 because it's essentially the same as a 4l80e without the electronics, overdrive, and TCC lockup (and I already have one that came out of another car). I don't mind banging the tunnel in a bit to fit a transmission that isn't going to explode every 6 months.

I may consider an 8.5" 10 bolt, but not a 7.5". I've broken the 7.625" rearend in my S10 several times also, even after gutting it completely and upgrading it. The 9" seems to be a standard bulletproof rearend that can be adapted to just about anything, which is why I'm considering it, but we'll see.

Why would 69 camaro spindles have more brake options than the S10? There are a lot of S10's out there, but not as many 69 camaros.

I will likely be getting a lot of parts from powerbyace.com, including the mounts and headers. For the pan, I'm thinking the Holle​y 302-​1 might be a good choice because it's ready to go. I wouldn't have to chop and weld a stock pan.

I'll have to disagree about manifolds vs headers. An engine is basically an air pump, and the more restrictive your engine is at one end or the other, the more power you lose. I wouldn't get nearly as much out of an aftermarket cam with manifolds as I would with headers.

Radiator is another thing I was wondering about. I'll look into Griffin.

Definitely keeping the fuel injection. No point in switching to carb imho.

I'll have to disagree about the subframe connectors too. They aren't hard to install, they make the car launch better, and keep the body from being damaged by twist. Body twist is still an issue even for a 12 second car.

All this feedback is really helping my research process! Thank you all again!

[jcrider]

I just finished up a 6.0 ls swap in my 74 hatch. I started mine before the power by ace parts were available, so I had to make my own headers and mounts. I found that the ls3 corvette water pump gave the most clearance. I also bought one of the aluminum fabbed oil pans off of ebay. It fit in the chassis beautifully and gave plenty of steering clearance. An ls swap in one of these cars is a lot more work than a standard small block, but the car runs awesome and I think it was totally worth it

[n8thenetninja]

Hello all, I got this car running last fall, and got it in a few races before the snow started. I thought I would post what I ended up doing, in case anyone finds this thread later.

To answer my own questions:
Headers: Powerbyace 1-3/4" headers.
I did have some fitment issues with these, but it was a combination of my car being a little bent up, and one tube being made wrong. ACE made it right and sent me a replacement tube. The rest was solved by shaving my front crossmember slightly.

Motor mounts: Powerbyace mounts. I had no issues with these. Great part

Transmission mount: powerbyace again. IF YOU HAVE A 75 VEGA you will have to shim the mount where the catalytic converter originally was. This was the only year for this floor pan, and as far as I know, ACE hasn't made a specific mount for the 75 yet. He seemed unaware of this one off floor pan until I mentioned it.

Radiator/trans cooler: I used https://www.championradiators.com/product/CC469, opened up my core support a bit, and made my own radiator mounts. This radiator has a transmission cooler built-in, and I daisy chained an external B&M SuperCooler into it as well.

Front Coil Springs: V6 H-Body springs worked great with the aluminum block

Car weight: Turns out my guess was spot on at 2800lbs curb weight. I'll post more details about that below

Possibly helpful information (at least to explain weight):

Engine: 2000 LS1 shortblock with 241 heads, ARP rod bolts, Lunati .660 double valve springs, TSP MS3 cam (.600/.600 238/242 113LSA), C5 Corvette water pump. ICT Billet upper drivers side alternator mount, FITech Ultimate LS Induction System.
Oil Pan: slightly longer story chronicled here: viewtopic.php?f=1&t=43766
Transmission: TH400 with shift kit, JEGS Street/Strip 3800-4100 stall converter, and JW Performance Ultra-Bell Bellhousing
Quick Performance 9" Ford 4-link rearend, with a cast iron Thunderbird center section, 3.73 gears, 33 spline spool, 1350 driveshaft yoke, 11" drum brakes. (QP Built a jig based on my stock rearend. They probably still have the tooling if you ask them for it.)
8-point mild steel roll bar
Procar front seats, no back seat, most of the interior removed (it was trashed when I got it)
South San Antonio Fab subframe connectors
85 S10 front spindles and disk brakes, with manual S10 master cylinder
14" 82 Berlinetta wheels with Hoosier Quick Time Pro 26x9.50R14 DOT Slicks on the rear

With this configuration, the car ran 12.00 at Bandimere Speedway, 5280' above sea level (probably 11.30ish at sea level). It had no rear sway bar, and a terrible front-end alignment, so it didn't launch super great.
Over the winter I added an Addco Rear sway bar, and a 1-1/8" front sway bar from a Monza, and switched to 799 heads. This probably bumped the compression from about 10.6:1 to 11.2:1 (really thin MLS gaskets), and should get better flow. I'll post when I know if that made it faster or slower (lol)

There's lots of other small details I'm leaving out, so if someone is trying to do something similar, I'd be glad to share information from my experience. I'm subscribed to this thread, so just ask. This was a ton of work, but totally worth it!

[monzaaddict]

I would like to see the spacer you made for the passenger rear leg of the ace transmission cross member.. Pictures and a measurement of the spacer height. Does it Align with the front seat bolt stud?

[n8thenetninja]

I used four pieces of quarter inch steel strap (ugly, but it works). It's very close to the passenger seat stud, but didn't interfere.
I should also mention that the passenger side of my car has been hit and repaired at some point, so it's possible that my seat stud is in a slightly different place than an undamaged one. I'd guess it's probably pretty close though.
[s]I'm pretty sure you're only going to find this floor pan in the 75 Vega (and variants), and not the 75 Monza (and variants).[/s] (see next post in thread) Why they did them differently for one year is anyone's guess.

transmission_mount.jpg

[monzaaddict]

75 Monza is the same as your Vega with the addition of the passenger side transmission body mount shifted back about an inch to make room for the v8 y pipe.

[n8thenetninja]

Ah. I stand corrected. Are you having similar transmission mount issues with the oddball 75?

[70styleVega]

As we all know, 1975 was a transition year for Vegas. The 1975s had the early 1971-73 four-link suspension, but the floor pans of the Monzas and later Vegas along other associated items like larger gas tanks.
I've even read that both shallow coil spring pocket and deep coil spring pocket control arms were in 1975s.

I never thought about these transition issues being a problem during an LS swap.
I'm starting a 75 Vega LS swap myself using the Power by Ace kit. I'm going to have to review the H-body FAQs and refresh my memory.

[n8thenetninja]

Pretty sure the 75 had its own floor pan for the year. The powerbyace transmission mount doesn’t fit quite right (unless he fixed it, but the website still listed the 75 with earlier models last I checked, which isn’t right) due to the recess for the catalytic converter, and is also very close to the passenger seat mount. I also continue to have problems with his modified f-body pan leaking. I currently have the engine out and hope to have someone else straighten it out or build me a new one. Not that you have any other choice in the market for swap parts, but be aware of the problems others have had, especially with a 75. Good luck!

[74_Vega_GT]

I'm starting a 75 Vega LS swap myself using the Power by Ace kit. I'm going to have to review the H-body FAQs and refresh my memory.

~~I bought PowerbyAces - 10505K1 71 - 75 4 cyl to 4.3 Chevy V6 kit w trans mount $ 263.24 and was unable to use his tubular bracketing with the Saginaw 4sp.setup. We went a different route.