Big Block Swap

Larry · April 11, 2003

Well, the time is finally here. After a couple years of collecting parts I am finally ready to stab fat block crate engine in my 78’ and send the tired ole little 350 down the road….actually the old 350 will be going into my buddies $500 75’ Blazer project. Click here to see the Blazer

Your all probably tired of seeing my signature read “454 on the way” but it has taken me quite some time to get to this point mainly because I used all brand spankin new GM parts where possible and of course, working on a budget. I should have some installation pictures up by the end of the weekend, but will probably not have it finished until early next week as it will also need to be towed to the exhaust shop for some new exhaust plumbing. Then I have to have the A/C lines custom made to allow the late model A/C compressor work on this old pig.

Contrary to my original plans it will, unfortunately, be carbureted for a while until my other buddy finishes his 6.5L diesel swap into a 1995 7.4L gas Suburban that way I can pirate all the throttle body fuel injection goodies from him when he is done.

Keep checking here and here for picture updates!

Torque Junkie · April 12, 2003

:thumb: Awesome man!

Best of luck!

Larry · April 13, 2003

Here is quickie update.

The little 350 is out of the way and the 454 will be ready to install tomorrow. Post more pictures when time permits.

Larry · April 15, 2003

Update on 454 HO swap: Bad News

So there I am tonight about 10pm topping off the radiator with Dexi-Cool after about 12hrs worth of swapping, wiring and fit and finish work all excited to light this beast up when I notice a coolant leak on the driver’s side of the engine. No Problem…probably a hose or something. NOPE!

The coolant is pouring out of the side of the block at the head gasket right between the cylinder head and block! Boy what would I do to have just one of those GM Powertrain union jerkoffs up in Tonawanda that don’t give on fuzzy terd about their craftsmanship sitting my garage right now!. Mind you, this is a brand spankin new GM Performance Parts 454 HO Gen 5 block.

Now I get to rip the intake and head off to replace a head gasket!

Kansas Kid · April 15, 2003

I'm pretty sure I would have gone through the roof when I found that head gasket leaking. All that time and effort put into the swap just to have something go bad that you had no control over.

As far as the TBI setup goes, will the stock computer run that big beast? I've fairly seriously looked into swapping the 350 in my truck for a GMPP HT383 later this summer, and have been told that I might need to get a custom burnt chip depending on certain variables. Think you will run into anything like that, or will the stock setup be ok? Just kind of curious to see how the TBI setup handles so much more power over that 95 454.

Larry · April 16, 2003

Yeah, Kansas I will defiantly need to have a PROM specially burnt for this beast whenever I throw the TBI EFI on it if TBI is indeed the direction I go. That is a long story about all the details on hardware and software to inject this thing with a OEM GM stuff. We’ll have to chat more about that later.

Well, I found the problem and turned out to be worse than just a head gasket. It turns out the cylinder head has a defect in it and will need to be replaced. If you look closely at the head picture you will notice a divot missing out of the corner next to the water jacket. I should find out tomorrow about warranty details.

I yanked off the head off in record speed today…just a little over 2 hours. Boy am I glad I went to college and don't have to spin wrenches everyday to make a living anymore. I am tired man!

Before teardown

After teardown. Very pathetic view of a brand new 454HO with zero miles on it, eh?

Torque Junkie · April 16, 2003

Oh man, Larry. I too would be

Hopefully they get that head warrantied for you.

Larry · April 17, 2003

Well, the head is on order from GMSPO in Lansing, MI and will not be here until Monday the 21st. The head will be bear so I will have to swap all my valves and hardware over to the new head plus lap them and check the seating. This means I probably won’t have the engine back together until late Tuesday or Wednesday. Then I have to tow it over to the exhaust shop to have the new exhaust and phony flowmasters put on it, of course now I have to reschedule the exhaust appointment and hope they can still working in and out in one day as I don’t want the truck sitting around in the exhaust shops bad neighborhood for long. After it is drivable I need to get it over to my favorite Napa store for my buddies can make up some A/C lines to allow the late model style A/C compressor adapt to the old style condenser and receiver dryer.

Oh, yeah…no warranty on the head as I lost the receipt from when I bought it back in 2000 and the dealer I bought it from in Chicago went under over a year ago so I cannot pick through their records either. I could probably use the buddy network of peers I work with but all GM is on Easter Vacation until next Tuesday. By the time I can get somebody’s help within the company I could already have this thing back together. Due to the time constraints I am working with I am just going to eat the cost the $300 head and move on. Pissy, but I will move on.

This seems like an awful lot of work and frustration to be a fricking hobby! Gee, I can’t wait to see what kind of mess I can get myself into when I fuel inject this thing later this summer.

Larry · April 24, 2003

Today the 23rd…still no cylinder head.

GMSPO’s inventory was wrong and they had to order the head from GM Powertrain now I won’t get the head until the week of the 28th. That sucks because I have to be in Pittsburgh, PA for a couple days that week and will not be able to work on it until probably the weekend.

Were talking a big block chevy cylinder head here not rocket parts…WTF does it take 2 weeks to get a #### head?! AGH!!

Larry · May 1, 2003

Well, I finally got the head all put back together and back on the engine this past weekend and she runs SWEET! No leaks now either!

I borrowed a buddy’s rollback this morning to take the truck over to exhaust shop to get new exhaust put on. Next week it will be heading over to another friends Napa store to have the new A/C lines made.

Here is a picture of my buddy’s official 1995 Brickyard 400 GMC roll back with as my truck was being loaded on it. This tow truck actually worked the track in the 1995 Brickyard 400 race.

Torque Junkie · May 4, 2003

Aweeeeeeeeeesome!!! :thumb: :thumb: :thumb:

Larry · May 13, 2003

In case you were all wondering…

After all the cylinder head problems, I finally got the exhaust put on and set the carb and ignition timing after I could finally hear the engine run.....without blowing my ear drums out as I did before the exhaust was hooked up. The exhaust turned out very nice after my buddy bent me up some 2.5’ aluminized pipe with a couple V-Force look alike and sound alike Flowmaster knockoffs. He did a real nice job on the angles, welds and fit and finish. He also left me an oxygen sensor port for when I add fuel injection later this year....all for 250 bucks.

Man, I have to tell you, this crate big block runs very very strong especially when stepping up from a half dead 350 small block. I might even venture to say this pig pulls as hard, if not harder than my 8.1L in my HD even though this 454 is still only carbureted for now and running on tall 3:73 gears with 36" tires.

Aside from fuel injection, gears and lockers, my next immediate chore will be to have the A/C lines made to allow 2000 C/K truck A/C compressor mate up to the old 78’ condenser and receiver dryer. Gotta have A/C here in the southwest in the summer especially when the mercury pointer hits 108 degrees for weeks on end in June and July.

Since every picture hosting website eventually punks out on their obligation (umm...can you say www.mychevytruck.com with the Enthusiast World BS icon appearing in this thread..... ) and I cannot post any pictures click here for the entire and ever growing engine swap pictorial page.

I also just added a set of WARN 4Xflairs so those pictures will be showing up shortly.