I'm Going To Build A 650 HP 496 With 781 GM Oval Port Heads

[Bextreme04]

Still impressive, but actaully power starts to fall off a bit at 5K.

It loses 1hp from 5900 to 6000 rpm... so I guess 5900 was the peak.

@bucket,

How did you know it was a Mark IV? I don't know that much about how to look at an engine and tell what it is. I'd be interested in knowing how you know what it is.

The number of timing cover bolts, mechanical fuel pump boss, and 2-piece rear main seal are dead giveaways. A Gen V would have a 1-piece rear main and most likely no mechanical fuel pump boss and a Gen VI would have only 6 timing cover bolts, 1-piece rear main, and no mechanical fuel pump boss.

 

[Mark Jones]

That is quite impressive.
600 foot pounds all the way to 6,000rpm.

@Mark Jones , will this go into your truck for track testing to see what it will do in the 1/4?

No, it was built for a customer. The 327 is staying in my truck until I wring every last bit of performance out of it. I'm moving to TX and my plan is to run 11s in Houston's excellent air.

 

[82sbshortbed]

No, it was built for a customer. The 327 is staying in my truck until I wring every last bit of performance out of it. I'm moving to TX and my plan is to run 11s in Houston's excellent air.

Well, let me be the first to welcome you to Texas! I'm not far outta Houston either. Just a tip. I wouldn't live in Harris County. Brazoria County is much better. Cheaper taxes,insurance and no Democrat mayor. Plus traffic like a mf in Houston. Lol

Let us(Texans)know when you make your move.

 

[bucket]

@bucket,

How did you know it was a Mark IV? I don't know that much about how to look at an engine and tell what it is. I'd be interested in knowing how you know what it is.

In the first pictures of the block, the biggest giveaway that my eyes saw was the pan rail. The later blocks have two oil cooler ports in the pan rail, back by the oil filter mount area. Then there's all the other details that @Bextreme04 mentioned.

 

[Mark Jones]

Well, let me be the first to welcome you to Texas! I'm not far outta Houston either. Just a tip. I wouldn't live in Harris County. Brazoria County is much better. Cheaper taxes,insurance and no Democrat mayor. Plus traffic like a mf in Houston. Lol

Let us(Texans)know when you make your move.

Horse Shoe Bay

 

[WFO]

Horse Shoe Bay

Lake LBJ?

 

[Raider L]

My truck weighed, wet (full tank, all fluids up and nothing in the truck that wasn't there rolling out the factory door) 3900 lbs. after I finished rebuilding it back like new. Now that is about four hundred pounds lighter due to the fact I used aftermarket bed parts. The guy who rebuilt my engine was a REAL street racer. He told me to get my truck to 12 seconds I'd have to be pulling about 500 HP! Not knowing any math on that I was shocked. REALLY! So if you're going to put that motor in your truck you'd be in the mid 11's? Of course our trucks are bricks going down the road.

 

[Raider L]

@bucket,

Well, that went right over my head. I never learned any of that sort of thing. My life went in another direction. But I sure do appreciate seeing a good engine when I see one. And I appreciate a man who knows what he's doing with them. Good work.

 

[Mark Jones]

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My truck weighed, wet (full tank, all fluids up and nothing in the truck that wasn't there rolling out the factory door) 3900 lbs. after I finished rebuilding it back like new. Now that is about four hundred pounds lighter due to the fact I used aftermarket bed parts. The guy who rebuilt my engine was a REAL street racer. He told me to get my truck to 12 seconds I'd have to be pulling about 500 HP! Not knowing any math on that I was shocked. REALLY! So if you're going to put that motor in your truck you'd be in the mid 11's? Of course our trucks are bricks going down the road.

I have a customer in Canada with the same long bed truck as mine, 3.42 gear Turbo 400, not gutted, probably around 4300 pounds with a 496 it runs 11.40s but thats at altitude, should run 11.0 down low. Most of you on this forum know my shop/race truck runs 12.80 @ high altitude @ 4000 pounds with a 327 making 445 HP corrected HP and 331 observed HP @ 6338 altitude. If I was to put this 496 in my truck with a gear change I can guarantee 10s @ Houston. Personally I'am pretty sure my 327 will run high 11s in TX and if it doesn't its a drive shaft away from doing it.

And heres the math:

125 @ 4200 = 647 HP
1320/125 = 10.56
Throw away 3 MPH for being truck and there you have it.

 

[82sbshortbed]

It's about an hour Noth west of Austin in Llano

 

[Mark Jones]

It's about an hour Noth west of Austin in Llano

Although I do live in California as well, I'am sure its crossed your mind-I Ain't no libby.............

 

[82sbshortbed]

Although I do live in California as well, I'am sure its crossed your mind-I Ain't no libby.............

That's good because we don't need anymore of them. Lol

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[Waylon]

Mark are you going to open a shop in Llano??
Maybe do a little work for the Martin Brothers?

You will be about 3 hours from me. I’d love to bring you a set of 781’s to work your magic on. I’ve already done some port work/gasket matching so you might not be able to determine core shift on them.

 

[Bextreme04]

My truck weighed, wet (full tank, all fluids up and nothing in the truck that wasn't there rolling out the factory door) 3900 lbs. after I finished rebuilding it back like new. Now that is about four hundred pounds lighter due to the fact I used aftermarket bed parts. The guy who rebuilt my engine was a REAL street racer. He told me to get my truck to 12 seconds I'd have to be pulling about 500 HP! Not knowing any math on that I was shocked. REALLY! So if you're going to put that motor in your truck you'd be in the mid 11's? Of course our trucks are bricks going down the road.

3900lbs?!?!? Mine is almost 6,000lbs

 

[Vbb199]

3900lbs?!?!? Mine is almost 6,000lbs

I think "someone" laughed at "someone else" for having a 2wd

Well nows "someone else's" chance to laugh at "someone" for having 4x4

Hahahahahahahahahahaha