Just showing some pictures of my 454 swap process using H8013 headers... If I knew it would be this bad, I may have gone with the $500 hooker headers... I'm not buying $1200, so I didn't wanna make a big deal out of the headers, but I also didn't want 1 3/4 primary headers... Unlike the 1 3/4 Patriot H8012 headers, you have a LOT of hacking to do, and I was very afraid of my chassis being hacked as much as it ended up being... I still don't know what else I'll need to do to get an exhaust system started... I will apparently have to weld at least one bolt to the header on the passenger side; like the H8012 headers, these dropped on on the driver's side, after the motor mount modification... On the passenger side, I started doing what booboosean did, but I realized that the header may have to be bent... Being that exhaust shops & junk yards (they have torches) suck here of all places in the NYCMA, they couldn't bend my header except for a fraction... I ended up having to heat up and dent the header myself because after they heated it up and TRIED to bend it, they tweeked the longer pipe that runs the length of the block, making it more difficult to figure out how much I had to chop away from the chassis... Once I figured out all my problems, I realized that a hacked up my chassis more than I needed to, but between getting married to this and get angry along the way, I think it'll be alright... I think it would be better to bend the header if you can (but do it properly) AND hack out part of the chassis... Now the pictures I have posted here (or will post) don't look too well, but after I hacked everything that I hacked, the chassis was still sturdy, but it was scaring me! LOL! After welding in a piece of angle iron where I could, I hit the section with a hammer and it sounded like a normal chassis that you would hit with a hammer... I hit it with a hammer previously before I welded it and it sounded kinda hollow... If I were to do this again, I would cut straight down in a straight line, and then put in a piece of angle iron and weld along the whole entire cut line... What I did will be suitable, and I may decide to add a thin piece of steel metal over everything, but I don't want to add more metal if it's going to make the header NOT fit... The header ends up being at LEASST 1/3 of the way SIDEWAYS, INTO the chassis... The other Patriot headers seems like they are a breeze compared to what I did here... I did this all with the engine installed, and I don't think you'll be able to go through the trouble of taking the engine in and out... Otherwise, the passenger side header fit in from up top... I tried to show as many pictures as possible getting to the point that I ended up with... This is my first post, so I hope to get these pics up at the same time or shortly thereafter... I will also include some pics of my motor itself... Mike...

 

more pics

 

more pics, showing the fact that I was using a gates tensioner and I had to switch to a dayco tensioner because the front of the tensioner was hitting the hood... Do you like that belt system???

 

Will post more pics soon with header installed, so you can see what I did better...

 

HOLY.....

What motor mounts & trans mount?? What heads??

 

The vehicle came with a V6, so I had to buy NEW motor mounts (the stock V8 mounts) then I drilled out the rivets and put the polyurethane energy suspension mounts in... The motor dropped in like butter! I did this swap 10 years ago, so I knew that would all fit in, but I had purchased Fabricated aluminum valve coverts but they didn't fit the passenger side! I just ordered chrome stamped steel valve covers because that's what I had last time... It's a Generation 6 454 block with Mark IV 990 casting rectangle port heads... Since it's a Gen 6 motor, it came with a roller cam, but I bought a new take out cam from a 502 crate motor... I have a 489 rotating assembly; 4.25 stroke, .030 over, with longer rods and relocated pin heights, approx 10.5:1 compression... I was thinking about buying spacers and longer bolts for the stock crossmember so I can fit the exhaust system inside the frame rails and put the exhaust on top of the crossmember... The whole exhaust/crossmember setup isn't set in stone yet... Kinda doing it, "on the fly"... I just wanna get the header in first...

By the way, that is a SMALL BLOCK/4.3 liter bracket system on a big block!

 

Also, I bought a new gas tank and I gonna use the stock electric fuel pump with a special regulator that will knock it down to carburetor pressure... The generation 6 motor has NO FUEL PUMP PROVISION! I had to make the return line LARGER than the main gas line for this to work... I will be modifing the in tank pump housing to acceot a 1/2 inch return line inside of the 1/4 inch line currently there... This generation 6 motor has a reluctor for a crank sensor on the front of the motor, so I purchased a crank sensor and the associated wiring harness and I want the sensor to ground the fuel pump relay so the fuel pump will not continue to run when the key is on... I'm not sure how I have to wire it yet, but in theory, I think my idea will work...

 

Is the Gen6 Bigblock taller than the Mark4??

I've read that poly will raise the motor some, so if the block is taller than a standard deck, possible the 2 differences put the flange that far into it??

We plan a Bigblock next spring, so I try to keep up on the Bigblock threads.

 

I've heard people saying that the block stands taller with the poly mounts, but I really don't believe it because the inserts fit inside the same place as the stock mounts... Remember, the mounts sit on an angle, if they were even a little but higher, then the holes wouldn't have lined up like butter... The generation 6 is physically the same engine as the Mark iv... It's just that they are balanced differently, have roller cams, and they USUALLY don't have a fuel pump boss... I think that the H8013 headers are just plain different... If Patriot were smart, they would make a mirrored copy of the driver's side header and then they would fit awesome...

 

Let me add, that my valve covers woes are because I want to keep the a/c system in tact... It will be a fast street car, NOT a race car... I'm older now, I want to enjoy it... I actually think I'll like the chrome valve covers better... I never liked high valve covers, and I wasn't impressed with the look anyway... Can't wait to get the chrome valve covers in...

 

Ours will be street, strip visits once in a while.

Gotta tame the " GO FAST " bug sometimes!!

 

rectangle ports, roller cam, along with extra 35 cubic inches will be fast enough... My last 454 camaro, I drove it everyday! Exhaust used to bang a little bit on the driver's side because it was hard to stuff the 3 inch exhaust there... NOW I have the panhard rod relocationing kit and I should be able to run true duals and I will never bottom it out or hear banging noises...

 

After getting this header in, it was a pain, but I definitely took out more than I needed, but the process was deceiving... The metal that was hardest to hammer was where a thicker piece of metal meets the floorboard... I tried to show it in pictures, but my 1.3 megapixel camera on my cellphone stinks... I had to also take metal out for the flange to clear but the metal at the base of the chassis didn't want to bend, nor did I want to try very hard in order to keep soem rigidity... If you look straight up at the header flange, the flange isn't visible for that one hole that is recessed in the frame... But if you bolt a 3 inch pipe to it, it should clear, maybe with a little massaging... Retracting what I said earlier, this wouldn't be so bad in hindsight... Of course, having better metal available and a better welder, with more space, in a less than 95 degree garage would have helped immensely, LOL...

 

couple more pics...

 

Like I said, it was very deceiving, trying to figure out how much to take out and the angles were confusing... I thought when that guy torched and slightly bent the header that he tweaked it, but he apparently didn't because, as you can see, it fell right into place... There was no need for me to "ding" the header...

 

This repair is a little scary for me, I would have liked to seen more metal replaced to secure this area of the frame. but thats my opinion from the photo, in reality it may be stronger than it looks. also how did you mount the brackets for the accys my bolt holes dont lineup?

 

You're right, but it looks worse that it is... The good news is the header unbolts and lifts out from the front, so it could be done again... Maybe by someone else who had a tig welder... I honestly think it will be fine; been using an arc welder for 15 years, and although it isn't my best work by far, it wasn't worth setting the garage on fire or being hit with molten metal... A few simple tack welds is really all you need in this case... There is a LOT of supporting metal all around the area and in fact, it seems like the majority of the support is on the outside of the frame, not inside, or in particular, right where the chassis is in question...

As far as the bracket system goes...

I paid $130 plus shipping for those few adaptor brackets, then I had to buy the original 4.3L brackets, then I had to buy ALL the accessories... the AC compressor, power steering pump and pulley, delco alternator, tensioner, idler, aluminum reverse water pump, a GM performance water pump pulley(for $27.00 it was worth it! You can knock someone out with the thing, it's SO strong!), and then I bought 454 underdrive pulleys...

On my last 454 camaro motor, I actually went to the dealer and purchased all the brackets separately for a 1991 Truck (they were all available in 2000) and it did NOT look THIS NICE! It costed me about $400 from the dealer and the alternator bracket BARELY dented the hood upwards and the power steering pump sat lower, so the pulley was hitting the power steering box, so I had to use a Grand Am 4 cylinder pulley with 6 ribs in order to have power steering.. It had a nice feel, though... Steering felt tighter after that mod...

Pictures show the brackets and the motor mount modification for installing the driver's side header...