[78 GHOST]

Bart, doesn't this engine come with a 2 year 24,000 mile warranty? Frankly I think this is one of the coolest ideas in a long time.

[andrewb70]

Just to clarify, the LS7 heads and the LS3 heads are different. Some noticeable differences are valve angle, and intake port shape. The LS7 heads also use huge 2.25" titanium intake valves and 1.8:1 rockers, compared to the LS3/L92 2.16" intake and 1.7:1 rockers.

Andrew

[b-man]

Originally Posted by Lemans64

Are u gonna change out the front springs or just cut a coil, the weight diff of the engine should make it sit high?? I used the stock replacements in mine, but have SBC and had to cut 1 coil off to get the upper control arms off the rubber stops. just another though for the process. LOL.

Rick

I already have another set of Global West front springs that have been cut down, I'll put them in to replace the H-O Racing springs that are in there now. I'll almost certainly need to trim them down even more.

Originally Posted by 78 GHOST

Bart, doesn't this engine come with a 2 year 24,000 mile warranty? Frankly I think this is one of the coolest ideas in a long time.

The LS3 crate engine does come with a 24 month warranty.

Originally Posted by andrewb70

Just to clarify, the LS7 heads and the LS3 heads are different. Some noticeable differences are valve angle, and intake port shape. The LS7 heads also use huge 2.25" titanium intake valves and 1.8:1 rockers, compared to the LS3/L92 2.16" intake and 1.7:1 rockers.

Andrew

Guess I was confusing the LS3 heads with the L92 heads.

Man, is that LS7 ever something special!

I'm still learning.

Get a chance to measure your headers yet?

[andrewb70]

Originally Posted by b-man

......

Get a chance to measure your headers yet?

Here you go. From the frame rail to the bottom of the header is about 2.25" on the driver's side. From the bellhousing to the end of the collector it is about 12", again on the driver's side.

You should also give Jeff Schwartz a call. I talked to him a couple of days ago and he has some LS7 cams for sale.

Andrew

[b-man]

Originally Posted by andrewb70

Here you go. From the frame rail to the bottom of the header is about 2.25" on the driver's side. From the bellhousing to the end of the collector it is about 12", again on the driver's side.

You should also give Jeff Schwartz a call. I talked to him a couple of days ago and he has some LS7 cams for sale.

Andrew

Thanks.

Just now ordered my Edelbrock headers and engine mount adapters, Energy Suspension urethane mounts and Griffin universal 24" X 19" aluminum crossflow radiator.

I'll get in touch with Jeff and see how much he wants for the LS7 cam.

Bart

[andrewb70]

Originally Posted by b-man

I already have another set of Global West front springs that have been cut down, I'll put them to replace the H-O Racing springs that are in there now. I'll almost certainly need to trim them down even more.


.......

What's wrong with the H-O springs that you already have? As I recall they have a rate of 450lb/inch. Should be perfect. You may have to trim them, but the rate should be good.

Andrew

[ponjohn]

b-man- Hotrod put a stock LS7 into a 70 Chevelle. It went 10.80's at 12x.xx mph. It is a SICK bullet.

[TheMonkey]

Originally Posted by ponjohn

b-man- Hotrod put a stock LS7 into a 70 Chevelle. It went 10.80's at 12x.xx mph. It is a SICK bullet.

i'm not sure anyone would say that the LS7 is anything but a phenom. sick sick sick.

if you are talking about the recent HRM article where they thrashed through a bunch of GM crate motors through the yellow '69 chevelle? IIRC, they made a specific comment about the LS3 only 75 less horsepower than LS7 for half the price. ...would make that last 75 hp cost about $6,500.

[ponjohn]

Originally Posted by TheMonkey

i'm not sure anyone would say that the LS7 is anything but a phenom. sick sick sick.

if you are talking about the recent HRM article where they thrashed through a bunch of GM crate motors through the yellow '69 chevelle? IIRC, they made a specific comment about the LS3 only 75 less horsepower than LS7 for half the price. ...would make that last 75 hp cost about $6,500.

Yes that is the article. I am not saying B-man SHOULD use the ls7, just saying it is a very impressive piece.

[andrewb70]

Originally Posted by TheMonkey

.....would make that last 75 hp cost about $6,500....

Micro economic theory. See Law of Diminishing returns. Also see marginal benefit vs. marginal cost analysis. Sorry I couldn't help it. We are going over all that stuff in a couple of my MBA classes. LOL

Andrew

[b-man]

Originally Posted by andrewb70

What's wrong with the H-O springs that you already have? As I recall they have a rate of 450lb/inch. Should be perfect. You may have to trim them, but the rate should be good.

Andrew

Figured I might try the set here that's already been cut first. The H-O springs are still fine.

Bart

Originally Posted by TheMonkey

i'm not sure anyone would say that the LS7 is anything but a phenom. sick sick sick.

if you are talking about the recent HRM article where they thrashed through a bunch of GM crate motors through the yellow '69 chevelle? IIRC, they made a specific comment about the LS3 only 75 less horsepower than LS7 for half the price. ...would make that last 75 hp cost about $6,500.

I saw that artice and it convinced me to get started. The LSX engine family is pretty much the cream of emissions-friendly and fuel-efficient V8 street performance engines. The fact that the all-aluminum versions are easily 1/3 lighter than most any iron V8 is just the icing on the cake.

The 505 HP 7.0 LS7-powered Z06 'vette is rated at 14/24 city/highway, the standard 430/436 HP 6.2 LS3 'vette is rated 16/26.

Pretty incredible, 11 and 12-second cars that can get such good fuel economy.

Even the lowly 325 HP 5.7 LS1 in my '02 WS6 automatic runs mid to low 13s without even trying hard. It's bone stock, all the way down to the cast iron exhaust manifolds, 2-1/4" headpipes off the cats joining into a 2-3/4" single exhaust pipe. Regularly gets 18 in the city, 26-27 highway.

[Karch]

Hi Bart,

First, please excuse me as I have not read the entire thread, but wanted to offer a few points.

I am good friends with West Coast Cylinder Heads in Reseda, and as such, I have been hearing nothing but great things about these LS motors.

Well, earlier this year, I broke down and bought a Trailblazer SS with the LS2/4L70e.

As such, and being such a research junky, I have learned quite a bit, and gathered some things that may help you.

My SUV is about 4800 lbs with driver, has 4.10 gears, and the LS2. These factors are rough on the transmission, as you would probably guess. My Trailblazer brothers, some of which are going pretty fast (low 10's), are beating up their transmissions fairly often.

As such, there are a few names that they all swear by in the transmission circles, and I would be happy to PM you the names or posts that discuss them.

I purchased HP Tuners software, as I hope to play with this more at a later date, but also got a mail order tune from one of the Trailblazer SS (TBSS) guru's, which I have been quite happy with.
Basically, the ecu uses 2 credits on HP Tuners.

Since I have the HP Tuners, and 6 credits left, I am thinking about grabbing one of the new GM LS conversion kits and implementing that onto my '65 455 instead of Megasquirt, but that's another story.

Another point I have realized and been told is the LS2/LS3's really wake up with cam changes, but the LS3 are really sensitive to nuances in the cam...off just a bit and it really loses on the low end.

Anyways, if I can be of assistance, feel free to ask. I don't have a lot of first hand knowledge, but I've been reading countless hours, and being an engineer, I take it from a practical standpoint...not intersted in peak numbers as much as efficiencies while still maintaining driveability.

Good luck.

[JC455]

Hey Bart,
A couple of random thoughts...
1) You can get an upgraded LS3 w/ the GM HOT cam for just a little more money than the stock LS3.
2) Nevermind- you already got an oil pan.

[455HOGT37]

Originally Posted by andrewb70

Just to clarify, the LS7 heads and the LS3 heads are different. Some noticeable differences are valve angle, and intake port shape. The LS7 heads also use huge 2.25" titanium intake valves and 1.8:1 rockers, compared to the LS3/L92 2.16" intake and 1.7:1 rockers.

Andrew

Good thread! I'm planning on doing the swap into my 68 ElCo, but I'm using the 5.3 and trans that is currently driving my Yukon around.

As to the LS3 vs LS7 heads, certainly the port shape is different. I just replaced the exhaust on my 08 LS3 Corvette with the commplete Z06 system. The "Z" manifolds are round port, while the LS3 is D port. Same spacing of course, so it bolts up fine.

As for fuel tanks, I have heard that the late Caprices (the rear drive, "bubble" style) have a in tank, plastic unit that is almost a direct bolt in to the old A bodies. Might want to check that one out.

[Karch]

I have one of these tanks, and 2 different p/u units. One is setup for in-tank efi, the other to suction out of for either external efi or carb.

Walbro makes a very good, affordable, pump that should support about 600 hp, normally aspirated.

[b-man]

Originally Posted by Karch

Hi Bart,

<snip> Well, earlier this year, I broke down and bought a Trailblazer SS with the LS2/4L70e.

As such, and being such a research junky, I have learned quite a bit, and gathered some things that may help you.

My SUV is about 4800 lbs with driver, has 4.10 gears, and the LS2. These factors are rough on the transmission, as you would probably guess. My Trailblazer brothers, some of which are going pretty fast (low 10's), are beating up their transmissions fairly often.

As such, there are a few names that they all swear by in the transmission circles, and I would be happy to PM you the names or posts that discuss them.

I purchased HP Tuners software, as I hope to play with this more at a later date, but also got a mail order tune from one of the Trailblazer SS (TBSS) guru's, which I have been quite happy with.
Basically, the ecu uses 2 credits on HP Tuners.

Since I have the HP Tuners, and 6 credits left, I am thinking about grabbing one of the new GM LS conversion kits and implementing that onto my '65 455 instead of Megasquirt, but that's another story.

Another point I have realized and been told is the LS2/LS3's really wake up with cam changes, but the LS3 are really sensitive to nuances in the cam...off just a bit and it really loses on the low end.

Anyways, if I can be of assistance, feel free to ask. I don't have a lot of first hand knowledge, but I've been reading countless hours, and being an engineer, I take it from a practical standpoint...not intersted in peak numbers as much as efficiencies while still maintaining driveability.

Good luck.

You can either PM me on your transmission contacts or post the links here, any help is much appreciated. I certainly want a strong transmission that will handle a good beating on occasion.

I want to be able to keep some sort of lockup converter, but I've heard they can fail from high-performance use, any comments?

There's a good chance I'll leave the stock LS3 cam in there. I want this engine to run well down low in the RPM range for good gas mileage, that's half the reason I'm doing this swap. Where I live the main roads are 50 MPH, 1600 RPMs at 50 MPH will be where I'm running a lot. I'm also considering warranty issues here, I doubt the warranty would stay in force if I tore into it to swap cams. Hopefully the oil pan swap won't be a warranty issue.

I'm pretty sure the best average power will be had with the stock cam.

Anyone up for a dyno sim comparing average power numbers between the 204/211 .551/.521 lift LS3 cam and the 211/230 .560/.555 lift LS7 cam in this engine?

Originally Posted by JC455

Hey Bart,
A couple of random thoughts...
1) You can get an upgraded LS3 w/ the GM HOT cam for just a little more money than the stock LS3.
2) Nevermind- you already got an oil pan.

I saw the 480 HP LS3 with the GM hot cam, another 6 or 700 bucks for 50 HP is pretty good. I think I need that $600 to pay for my engine swap headers instead, they will add about 30 HP and make the exhaust hookup easy.

Originally Posted by 455HOGT37

Good thread! I'm planning on doing the swap into my 68 ElCo, but I'm using the 5.3 and trans that is currently driving my Yukon around.

As to the LS3 vs LS7 heads, certainly the port shape is different. I just replaced the exhaust on my 08 LS3 Corvette with the commplete Z06 system. The "Z" manifolds are round port, while the LS3 is D port. Same spacing of course, so it bolts up fine.

As for fuel tanks, I have heard that the late Caprices (the rear drive, "bubble" style) have a in tank, plastic unit that is almost a direct bolt in to the old A bodies. Might want to check that one out.

Mike,

The 5.3 is great little engine with great power and super fuel economy, I was impressed with the 327 cube/327 HP carbueted one tested in the Hot Rod crate engine comparo.

Already purchased a '64 direct replacement tank that's EFI-ready from SPI, but I'm sure that info will be valuable to someone here.

Bart

[gto65lvr]

Hmm I cannot imagine the amount of work involved to change cams would be worth the expense and Bart my last LS1 I went from the stock cam to something a bit wild TR230/236 cam it pulled and sounded just wild but lost all the low end RPM off idle putting in traffic and made it a bit tempermental. I had the 6sp and kind of was a little miffed at that.

it was in a 2000 vette. I am sure a stock LS2 or 3 with a tune will be just what you are looking for hell thats over 400HP at the crank and with that in an LS motor it is a whole different world.

I have 388HP at the tires and it was brutal That was the LS1 with cam, headers, ls6 intake and a real close tune.

YOur totally on the right track and if you would I would very much like to see a tally of parts and $$ you are at for this project. I know from the reading you are doing this the best way both parts ease and $$ wise without skimping.

I have been doing some research on this too but have had all the same questions

engine,trans placement
oil pan depths
etc

Keep it going

[b-man]

Originally Posted by gto65lvr

<snip> Your totally on the right track and if you would I would very much like to see a tally of parts and $$ you are at for this project. <snip>

So far:

SPI EFI-ready tank - $429 + $76 ship
GF872 filter/reg - $45 + $7 ship
Autokraft pan kit - $430 + $20 ship
Chevelle repro frame mount brackets, pair - $78 + $14 ship
Edelbrock engine swap headers - $600 + $12 handling fee*
Edelbrock engine mount adapter plates - $65 *
Energy Suspension urethane engine mounts, pair - $72 *
Griffin 25202-X 24" x 19" aluminum universal radiator - $196 *

$2044 for this week.

More to come.

[Karch]

Bart, I'll get you the links when I get some more time. I just got back from the Lakers game (they won!).

As for the converter...the trick ticket seems to be an expensive triple disc unit...made by Yank. They can handle WOT shifts while locked, which I am reading is good for another mph or so in the 1/4. Not that you need that, but with these trucks and trannys, they all recommend keeping the lockup feature.

I'll send some links your way, but the ones that are really touted are by FLT and RPM, both out of the midwest.

[Colin Frolick]

http://www.hotrod.com/techarticles/e...t_2/index.html

http://www.carcraft.com/techarticles...ads/index.html

notice how, in the car craft article, power < 4800rpm is alot less with the bigger cam/heads.

a stock cam sounds like a good idea. i've thought about putting a bigger cam in my ls6 powered car... but i like how i can launch it in 3rd gear without stalling, chirp the 295's shifting into FOURTH, and get 28mpg. ur Tempest better have some traction b-man.

you're making me think i should do this my white tempest too