Help!!! 74 Laguna S-3

I just found another toy to spend time wrenching on. I found a mostly original 74 Luguna S-3 w/a factory 400 backed with the turbo 350 with a 2500 converter with the "slap" style shifter (I am still learning about this car. Its the auto where you slap it at a 1 o'clock to shift it. The original freshly rebuilt 400 has been bored 30 over with a mild street cam. it has a good start for a decent street car however it has way more torque then i can actually use right now. I just recently came across a 8.5" 4.11 posi rear that i think will fit but I do not know if this will swap into the factory 10 bolt. I am not sure if the factory 10 bolt in 74 was a 7.5 or the 8.5. Would anyone happen to know. I am trying to avoid pulling the cover if i dont have to. It has no moisture around it and if the posi unit will not work then i would rather not mess with it. If anyone could tell me i would greatly apperciate it. As you can imagine information is not real easy to find on these cars. thanks  

You got a sweet piece there man! Those '73-'74 Laguna S-3s are often overlooked for performance. You could still get a 454 in the Laguna in '73-'74. Foudn one recently but the guy won't come off it, so it continues to rot.

That car should have a 8.5" 10-bolt rear. Best way to be absolutely certain though is measure the ring gear in the current unit ot be absoultely certain. From the factory it should have the 8.5", but tha doesn't mean someone didn't swap it at a later date.

That chassis is the same as the 70-72 Chevelles/Malibus, basic GM A-body platform. You could even swap a 12-bolt from an A-body into your car with no problem.

THe 400 small block was a great torque motor because of it's long stroke. As long as the block's in good shape (sounds like it is) a good set of aftermarket heads and an intake will wake it up even more. Though one thing to watch with the 400 is cooling. Make sure the cooling system is up to spec or above. One good overheat was known to kill 400s because of the thinner cylinder walls.

What color is the car?  

It hasnt ran above about 165degrees. It does have a Performer RPM with a holley 750. It has a mild .470 street cam wich i would like to opt out for the .504/524 VooDoo cam. I am looking to get a nice choppy idle. The heads are single hump's that were freshed up but i would like to find a set of decent affordable heads to put on for the time being. I just took off the new 2 1/2 dual alum axhaust and put 3" resignators right off the headers. it made a nice power difference and it sounds mean (except for the idle). I just lucked into the posi rear with the 4.11 (which should make things fun) and a tunnel ram (which i am probably not gonig to use) the guy was also suppose to have a set of closed chamber 64cc heads but he gave them away before i got there. The car is dark red metalic with metalic dark blue flames. The (red) interior is perfect except the driver seat has a 2inch cut where the back and the seat portion meet. The body has a fist size dent in the A pillar and two line dents one on the roof and one on the quarter panel not more the 1" long. I got the car off a guy at work who lives in a snobby neighborhood where they didnt want a car that old sitting in the driveway. His loss my gain. I found out it use to be his father show car and it actually won a few small shows. The motor, trans and converter only had 2500 miles on it when i bought it. I through a set of cragar street stars on it that i had laying around fitted with mickeythompson sportsmns in the back and skinner ones in the front and it looks better. I took it to the track once. I went to help a buddy out with his car and he wanted to see what the old boat would run. it ran mid 14's at 98mph the sixty foot time was horrible with the 273 or 278 open rear thats in it. It will spin the one tire as far as you want until you let out of it. That doesnt help times much and i think i had to have the longest single tire burn out of all times (haha). I figure what the heck for $800 I got a deal. It doesnt look like or run like a $800 car. I bought the car almost unseen just for the motor and trans to put in my camaro. Once i saw the car though i had to keep it(Im weak when it comes to different cars) . The only thing the car needed when i bought it was a set of shocks in the rear and the brakes needed to be rebleeded. People cant believe i got the car for that price. I drive it more then i drive my stingray or my camaro. i would like to find a aftermarket hood or atleast another hoood so i can keep the original and place a 3" cowl on another one. I am not sure what body parts would fit though like i said i am still learning.  

If you want a cam that gives you a "mean" idle but will make the car easy to drive ont he street, check out Comp Cams new Thumper line of small block camshafts, they're designed for what you want.

Head wise, if you're looking for something cheap and better flowing, see if you can score a used set of L98 Corvette heads from an early C4.

A cowl hood's tough, don't know of an aftermarket one. your best bet is to graft a 70-72 cowl hood onto a 74 hood.  

Humm i will have to check those cams out. I may have a line on a set of closed chamber 64cc bare heads from anothr buddy. I am not sure what type of condition they are in but in but they are free (other then the machine cost). Do you think they would be a decent set of heads for the time being? I really apperciate your responses thanks again.  

What castings are they? Factory GM heads or aftermarket?  

The heads were junk factory castings so i passed on them. I was just looking for somthing to flow better then the stock 76cc heads that the guy put back on this motor. I figured if i could find a cheap set of 64cc's it would bump the compression up and give me a little more for now and then i would buy a good set later when i found a deal on them.  

Hey 55 Guy, are you looking for a laguna ? I am selling mine  

Where are you located at? My project plate's kinda full (and wallet fairly empty), but I always know someone who's looking for a new project car.

What's the rundown on the car, and how much?  

GM used several rear axles, the code for what your car has is in the VIN number.

Most likely it's a 10 bolt 8.5 inch. There are two designs that can appear on this, one has an 11 inch diameter oval housing the other a 10 5/8's scalloped housing. Look for the casting numbers 410408N or 410409N on the main housing. There should also be a set of stamped numbers on the passanger side shaft tube that a dealer can use to specifically ID the thing. If you drop the drive shaft, the input pinion shaft should measure 1.625 and have 30 splines.

GM tossed some cuves between Chevy unique rear ends, corporate rear ends, BOP rear ends, the occasional Dana, and 12 bolt housings with 8.3 inch gears so if what I think it has isn't what it has, don't be too shocked.

Bogie  

hey are you still looking for a laguna i have a 1974 laguna 454 4spd matching #,s car if you are interested send me an email if not  sorry i ve tired to post a pic on my acc, but just cant figure it out  

iam in ky want my phone #?