Big Ass Engine

['86erfixer]

So when I blew my stock 305, I purchased the GM 350 HO crate motor and went crazy for it. Now, I've had it for a little over a year and it's ah ok. I need more HP. Is there anything I can do to this engine to see a real performance boost?

I've already decided to get an blown 454 and attempt to rebuild it in my off time (what off time?). Once that's done in 6 months, a year or however long it takes me I'll put it in the blazer. But for now, I'd like to juice her up a little bit.

You should know that I knew nothing when I bought the Blazer and basically have just been learning as I go. I've read countless threads here at CK5 and just recently began posting. Any info is appreciated, Thanks.

 

[ZukiJohn]

Once you go big block ....you never go back!!!

 

['86erfixer]

Yeah, there's been a number on them on craigslist lately and my will power is shaky at best. After all, I'm only human right?

 

[Fabrimacator21]

What 350 do you have?

Plenty you can do....

A set of AFR heads and a decent cam will make a big difference. If thats out of your price range then some cast iron Darts off ebay are great heads for the price.

Check out the 6.0 gen III motors though... Great off Idle tq and real easy to make power.

 

[Greg72]

What is the HP/TQ target?

It's pretty simple to decide once you know "the numbers" you want....

The bigger the numbers, the more cost-effective the BBC becomes. If the numbers are more conservative then the nod goes to a stout SBC, or even one of the plentiful LS motors that everyone seems to be doing now.

I will suggest that you build for TQ, not HP in a heavy truck but if you've been reading much around here you should already have seen that advice about eleventy-billion times.

 

[supersize75k5]

Once you go big block ....you never go back!!!

ha.. I went big block and have had several of them..

its all about the ls motors now though.

 

[American84K5]

Once you go big block ....you never go back!!!

Once you go Gen3 you won't go back

 

[Capt.D]

Once you go Gen3 you won't go back

Amen to that!!!! There's a Ram Jet 502 in my Jimmys future for sure....

 

[Merv]

What do you have for the rest of your drivetrain?

 

[Stomis]

Amen to that!!!! There's a Ram Jet 502 in my Jimmys future for sure....

What what? I thought the crate ramjet 502s were old school big blocks with new school FI and heads/manifolds.

As for power, your off your rocker! I 454 to push those little 33's?! I've got a mildly built 350 that I'm convinced has more into it than the PO told me. I have 3.73s and 36s and this thing puts you back in your seat when you punch it. I have a friend whose had alot of blazers and K trucks and he says its the fastest one hes ever been in.

I personally dont like the overkill horsepower boat but thats just me. I think I mildly built 350 would do you right and I KNOW a 383 would put a smile on your face!

 

['86erfixer]

Wow, thanks everyone. Looked around this site and the internet and maybe the ls is the way to go over a 454. But thats something I'm going to be doing as a project with my brother.

To get an oversized cam and new heads I would have to pull the engine and tear this one down right? Basically, I know that I want to go bigger and just looking for a quick way to get more out of this motor. My intentions are not to get huge numbers (tq & hp) outta this engine. Just something to throw me back in the seat a little bit. I'm assuming getting a bigger carb becomes useless at some point, but would I notice a difference if I went to a say 750 or is that just overkill?

As far as my drivetrain its all stock. I know its gonna have to be replaced, but not until I break it. I want to see just what it can handle.

 

[Stomis]

Wow, thanks everyone. Looked around this site and the internet and maybe the ls is the way to go over a 454. But thats something I'm going to be doing as a project with my brother.

To get an oversized cam and new heads I would have to pull the engine and tear this one down right? Basically, I know that I want to go bigger and just looking for a quick way to get more out of this motor. My intentions are not to get huge numbers (tq & hp) outta this engine. Just something to throw me back in the seat a little bit. I'm assuming getting a bigger carb becomes useless at some point, but would I notice a difference if I went to a say 750 or is that just overkill?

As far as my drivetrain its all stock. I know its gonna have to be replaced, but not until I break it. I want to see just what it can handle.

Lol my motor throws me back on 36s and its nothing but a 355 with a notch or two up cam, full long tube exhaust,TB spacer and aircleaner.

I think you'll find more improvement in a torque converter, servo, and shift kit. Thats the kinda stuff that throws you back in your seat, cause you can make gobs of power but if your trans aint throwing it right down its still gonna ease into it.



BTW LS motor FTW

O and on another note. You do NOT need to take the motor out to do the heads and cam. Theres more than enough room in our trucks to pull it off. just gotta loosen some mounts and throw a jack under the front of the motor to put the cam in.

 

[throttleissues]

I've always felt big-block trucks nose-dive too hard when you jump them. Maybe I'm just different. You could swap heads/cam on your SB without pulling the engine, just pull the radiator to make room to pull cam. If you're dead set on an engine swap, I'd look at the LS engines. Big power without the weight.

 

[jtrapani]

lsx 454. Small block 454 can't go wrong. Its only 15k.

 

[JDNobodi]

I've always felt big-block trucks nose-dive too hard when you jump them. Maybe I'm just different. You could swap heads/cam on your SB without pulling the engine, just pull the radiator to make room to pull cam. If you're dead set on an engine swap, I'd look at the LS engines. Big power without the weight.

Your not the only one! Although after the aluminum head swap the nose diving has lessened dramtically. Either way between a big block or ls motor you can't go wrong. A big block offers more overall horsepower IMO and are fairly cheap, but the LS motors also have alot of cool features. It all depends what type of wheeling your going to do with your blazer.

 

['86erfixer]

No extreme wheeling. Just camping and driving off road, being a redneck. But I want my rig to be able to throw my ass back when I want it to. I know not much of this is real explicit, but that's the general idea for my truck

 

[Stomis]

No extreme wheeling. Just camping and driving off road, being a redneck. But I want my rig to be able to throw my ass back when I want it to. I know not much of this is real explicit, but that's the general idea for my truck

Get a trans that puts the power to the ground first. I bet you'll be shocked how fast that 350 actually is. Also did you regear your truck?

 

['86erfixer]

No, I have never regeared my truck. I have the 700R4. I've had it tuned twice since buying the truck and am told everything is fine with it. Should I opt for the manual 350? I like having OD

edit: would a larger carb worth it, or pointless?

 

[JDNobodi]

Personally i would like seeing a blown big block blazer on here and it would definately be different than everyones else. The ls motors can produce plenty of power and would probably better for overall offroading and camping and would offer more driveabilty. The power that a blown big block can make always appeals to us rednecks and if your looking to really have your as thrown back in the seat thats the way to go.

 

[Stomis]

No, I have never regeared my truck. I have the 700R4. I've had it tuned twice since buying the truck and am told everything is fine with it. Should I opt for the manual 350? I like having OD

edit: would a larger carb worth it, or pointless?

Ok my friend, I'm gonna tell you what I know you most likely dont wanna hear deep down on the inside.

Your current motor is not lacking power. your just lacking the means to efficiently put that power down on the pavement.

Just because theres nothing wrong with your 700r4 doesnt mean theres nothing wrong with your 700r4. Let me explain, the trans could be functioning perfectly fine. That same trans came behind plenty of cars, 2wd trucks and god knows what else. The terrible truth about auto trans' is that they still slip whether they work perfectly or not. Components on the inside slip they are just suppose to. This slip creates comfort through shifts and heat at the same time which equals lost power.

You can start simple. Look into a shift kit and a servo. This will alter your transmissions shifting habits greatly. It will chirp tires, shift hard, and remove that sense of comfort when you mash the gas.

The next step is a torque converter. This will give you that thrown back launch feeling when you take off from a dead stop. its basically like dropping the clutch in a manual car when you punch it.

Next is your gears. Our trucks were undergeared from the beginning. with 33's and a 700r4 you should have 4.10s in the diff and i'm willing to bet your geared much higher than that. Gearing has a HUMUNGOUS affect on acceleration and fuel economy.

Please I beg you consider checking into some of these options before you go building some super motor. I guarentee if you do build some motor you'l still feel like its not all there.