400 sbc built for towing

[hook]

I have a 88 blazer 4 wheel drive with automatic transmission,373 gears and 33"tires. I have a 400 block bored 030 and crankshaft. I need help on selection of dart heads,cam,intake and carb. i will be using to pull heavy loads over mountains and trips to 1000 miles. thanks

[Mikey R.]

you can use the stock length rods or 5.7 rods. I prefer forged pistons over hyperutectics, but I know there are plenty of engines out there with hypers that run fine. keep the cam conservative, is this fuel injected? you're gonna have to get a custom tune in the computer. Also run the Performer intake and check out turbo city for their throttle bodies, cams and ECU tune ups. If going carb run the performer intake with either well built Qjet or 750 holley. Choose a cam that makes the best Torque up to 4,000 RPM. I'd use the vortec heads with stainless steel roller rockers too.

[want-a-be]

I would use the Dart 180s. Doesn't matter if it's the iron or aluminum ones. Around 9-9.5 compression. Not over 10-1 especially with the iron heads. The aluminum heads will be more pump gas friendly for the loads you'll be towing. But the iron heads will aren't a sacrifice in any way.

I'd use the airgap type intake. But I'd use the Holley type carb. I'm not a big fan of the AFB style carbs. No larger then a 600 cfm though. Here is a good example on the intake type I'd run....

http://www.dartheads.com/products/intake-manifold-special.html

On the cam,....I'd shoot for something like 216°-220° @ .050" on the intake and around 220°-224° @ .050" on the exhaust. There's no reason to have any more lift then .450". Might be something like .445" on the intake and .455 on the exhaust. Doesn't matter if your going to run the hyd roller or the hyd flat tappit. Thats what I'd shoot for. I'd target a Lobe sepperation angle ( LSA ) of something like 112°-114°. This will make a ton of vacuum for anything you'll need it for. Even if you wanted to run some kind of EFI instead of the carb.

This kind of cam, along with the intake/carb, cubes and heads will make a torque monster for you. :eek: Making peak torque right around the rpm range where you are going to want to be towing. :cool:

Hope this helps. If you need any more help let me know. ;) I've PMed you some contact info

Thanks, Don

[want-a-be]

Oh yea I forgot to say...make sure that you have the 400 block torque plate honed. It's a must.

Don

[hook]

thanks for information, I will definately be using a carb. which 180 heads are you talking about, the iron eagle platinum or pro1 platinum?

[want-a-be]

Either will do you great. Give me an e-mail some time.

Don

[Dart Vader]

We dyno tested one of our 372ci short block combos recently that would work well for your purposes also.

Peak hp was 400 @ 5,200
Torque curve was really flat - it was over 400ft/lbs from 2,400 to 5,200

It was running the 165cc SS Iron eagle Heads with an SHP block.

I'll be putting the video for the dyno test up on our video site before too long.

[want-a-be]

What were the cam specs on that build Dart Vader, if you wouldn't mind.

Don

[Awesome Bill]

you want the S/R head 170 cc, for this application with the 1.94/1.50. A 500 cfm Edelbrock at the most, the max torque curve needs to be under 3000 rpm. I would keep the camshaft @ .050 around 212 intake and 216 exhaust on a 114 l/sep. The intake manifold should be an air gap style with a heat sink spacer.

This engine will produce well over 450 lbs of torque. Anything over 4000rpm is a complete waste and not applicable for what you want here. With those tires, cruising rpm with that gear will be arond 1500 rpm. You want all TORQUE. I don't know what the others are thinking about here with a 750 cfm carb, that is not even close. @100% ve, your engine will not use anything more than a 470cfm rating. You will NEVER get 100% with exhaust and what your doing.

What you will get is tire smoking torque under 2500 rpm. You can do what you want, but my combination here will produce 15-18 mpg with no problems. If you want a product that works, call me.

[Dart Vader]

What were the cam specs on that build Dart Vader, if you wouldn't mind.
Don

224 Int/234 Exh @ .050 Duration

.465 Int/.488 Exh - Lift

107 Int/117 Exh - Lobe Centers

[hook]

i have found a set of 062 vortec heads, would there be much difference in them and the other stated heads? thanks for any info.

[Awesome Bill]

those head will work very well if that is the way you want to go. They do make really good power and torque. I would not even think of running any large type of camshaft with your application. Anything more than what I have suggested will just move the torque curve higher and lower total mileage. You can use it but your combination and what you want it for would suffer. It will just move the entire packages power curves upward and above the 2000 rpm range. TORQUE is hp!