craming a 8.1l in a 72 blazer
 

i have a 72 blazer and want to put a 8.1 in it with a allison tranny i dont have anything but the bare motor and tranny no ecu or tranny controll moduole i was just wondering if u guys can put me on the right path to get started.

thanks,
Brad

for induction i'd recommend a carburetor or stand alone efi system...as far as the tranny goes i'm not sure if it's feasible to do away with the computer controlled parts but you could always just go with a turbo 400 and a gear vendors overdrive if you need it, then selling the allison would make a good portion of your money back...it's either that or find a donor PCM and wiring harness

I'm going to stay with fuel injection and probably going to supercharge also

I'm not sure of they could help but you may check out speartech.com a buddy used them for a harness and shit to put a ly6 and 6l80 in his 77 Chevy. I'm not really sure if they deal with Allison's but it'd be worth checking out. If anything they could get ya going on the engine harness.

Ok cool ill try that.

I have another question does anyone know if the superchagers for the 8.1l in trucks is the same as the 8.1 marine motors. the reason i ask is bc i cant find anyone who makes one for the truck but i can for the marine motors.

Why does te 8.1 not have the aftermarket following like any other motor would have.

^because most people who build big block chevy's use the old ones as a starting point...the later models, while larger had some unpopular changes (can't say what off the top of my head right now) and parts interchangeability issues with the older engines which already had a hugely developed aftermarket...that and the relatively low production numbers make it a waste of time to R&D new products in many companies eyes.

google
496 into 04 silverado
That is my truck
I know a thing or 2 about 8.1's
mine currently makes 640hp 680tq to the wheels

thats badass thats what i want to do with this thing

how did u go about it

well I put forged pistons in it, zz502 cam and springs, ported heads and a turbo. Also made a custom intake but a raylar intake will get you there.

If you havent already looked raylar big power is the only aftermarket offering for them.
If you switch to a zz502 cam you have to change the firing order

It looks as if Dart Machinery is starting to offer a little love for the Gen VII engines, by offering a new iron block and heads. The iron heads are set-up for the typical 2.18 / 1.88 valves and have 306cc intake runners and 108cc combustion chambers. The block is set-up to use standard big-block Chevrolet rod and main bearings, has priority main oiling and has retained the use of metric fasteners throughout to keep things common with production parts. The bore comes in at a standard 4.250”, but I don’t know what their limit is.

Raylar and few others have commented that the block and heads arent as good as OE stuff. I sure wouldnt pay that kind of money for iron heads to have them flow less. Might as well buy raylars aluminum. The carb intake the runner design looks like an after thought look at number 7 runner fuel and air doing a 45 degree turn right before the port I dont know why they didnt make it like a ford single plane intake with equal runners with all a straight shot. It is like they took the port location added a carb mount and connected the dots.

Maybe, as from what I understand they developed the components as being replacements for the industrial market, but I couldn’t understand a company that knows as much about casting and performance to cast components that were worse off than the factory parts…….but it has been done before. I tried to download their pdf specifications to see if they listed a max bore limit on their block, but it gives an error. Even though the block has non-siamese cylinders, you would think they would give you enough meat to open the bores up little for larger applications, but then again if they were just replacement types, they may have not cared enough about what could be instead of what is.

more of they took a stock dart bbc and converted it for 8.1 usage. raylar has been helping them fix the issues

Should I try and run a factory ecu or do an aftermarket ego system

And another question is there software I can get to do my own flashing or do I have to pay someone? If I can is it pretty easy to use or does it take a rocket scientist to use it

If you want to tune it yourself I would run a megasquirt. I can help you with the setup etc

If I do that do I need the factory ecu at all or can I just do without it

Not needed

Ed are you running the MS3.X box with the MSD coil driver box? Or did you go sequential'ish ignition off the MS box?

I ran mine on a ms2 box and a ls1 6010 msd box
You can run it off of a ms3 but its cheaper and easier to run it the other way.

So if I do the msd box and I try to use a dash out of a 2005 or so truck with all the gauges still work without the factory ecu

Why would you want a dash that is vin locked to the pcm you will also need the bcm

Well what I want to do is take the interior out of a new truck and like the wiring harness that way I can have power windows auto lights interior lights dual climate controll a/c etc
Basically I want it to look like a 72 blazer on the outside but be a 2008 or newer truck on the inside.

well, thats the hard way to do it but thats up to you.

I can buy a new ecu for 80 bucks it's doesn't have a flash on it is there anyway to flash it myself or does a dealer have to do it

dealer or 600 dollar software or spend less then 600 and get a fully built megasquirt 2 and buy a used msd 6010 box and the software is free for both and you can tune it your self with out all the extra bs to worry about like traction control etc.

That's sounds like a better way to go my only question is by deleting the factory ecu will I lose anything as far as the dash goes

What software out there allows u to program factory computers

EFILIVE and I have the ability to flash it for you. PM me if your interested

Ok cool do if I send u the ecu u can flash it and send it back

Hey ED do you know what modifications u have to do on order to use the old bbc hrads

Not sure why you would want to do that but.. 3 head bolts are slightly different location. the center most upper and the 2 dowel locating bolts

so either re drill the heads or have the block holes filled and redrilled

Well as the older bbc have a better aftermarket as far performance heads intakes supercharges that's y I thought I would ask

What other options do I have besides raylars prices

HEll i would get it in the truck and running first :)

No I want to build it and put it on Nu engine run stand get it all broke in and all the bugs out of it then when I get done with the truck restore just slide it in

What heads and pistons do u recomind

Why are the whipple sc for the trucks a side mount style but the boat whipple sc a top mount I like the boat style better

Whats your budget like? I mean if you are pulling heads off, get them ported. I went from the stock exh valve size (if i remember correctly 1.72) to 1.88. kept the stock intake size 2.19. I would go turbo before wasting all that money on a s/c

Pics of my ported stock heads

http://i1239.photobucket.com/albums/...e/DSC02076.jpg
http://i1239.photobucket.com/albums/...e/DSC02077.jpg
http://i1239.photobucket.com/albums/...e/DSC02075.jpg
http://i1239.photobucket.com/albums/...e/DSC02074.jpg

About 5000 on the motor before boost but the money isn't the big deal I want to hit around 700-750 hp that's my goal

Well mine makes 750 now... and thats what i got in my engine