Installing a 454 in my 71 4x4 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**71blksuper4x4** · 10-03-2002, 05:29 PM

I know you guys have heard and answered this question before, but what are the procedures for dropping in a big block in my 71 swb 4x4? I know one idea is to put a 2-3 inch body lift, but I already have it lifted 5 1/2 sus. so I didn't want to do that. I have also heard that you can take a 73 crossmember and scoot it up on the frame, and take 73 big block mounts and somehow fit those in to keep from notching the firewall. I really do not want to cut the firewall on a cheyenne super, so if anyone out there can get me some tips, I would sure appreciate it. (I have already found the 73 components, just need to hear if it will work or not)

BLAZERMAN · 10-03-2002, 11:39 PM

Sent this info to Yukon Jack awhile back and he posted it on the message board. I dont know anyone who has done it but it looks like a good alternative to beating on your firewall or having to use a body lift. If you try it be sure to keep us posted.
http://67-72chevytrucks.com/vboard/s...threadid=24915

Truck Hippy · 10-04-2002, 12:42 AM

Hey. I did this swap several years ago with a 72' 4x4. I droped in a 454 and it was no sweat, The truck was a automatic (350 turbo) and i didn't have to cut or move anything. I had an HEI in it with no firewall problems. If i remember right, the only thing i did was on the drivers side there are 3 small bolts that come through from the inside of the cab that hold the gas pedel to the firewall. Make sure those don't stick out very far because that is where the valve cover lip will be and motor movement will cause it to hit. Also on the pass side firewall the valve cover lip is very close to. I don't remember if it would rub or not but i did put a small dent just to make sure it didn't rub. This was an A/C truck and every thing worked out fine. Just take it nice and slow and it should work out ok. E-mail me if you need any more info.

**breeh** · 10-04-2002, 04:46 PM

I just put a 427 in mine. I also added a 700R4 so I knew that I was going to be moving crossmembers. I moved the engine crossmember 2 inches forward. I also used high performance polyurethane motor mounts. The motor fits in there perfect with no interference problems. It sits in the right position so that a factory BB fan shroud also fits well. BTW, I am using a short water pump setup. Good Luck

**MJN** · 10-04-2002, 11:08 PM

My brother just put a 454 in his '72 GMC and the best way he was told was to move the engine crossmember ahead one inch. Then everthing else move forward too of course but thats all you have to do. then all the original linkage will lineup and be useable. He can also put both his hands behind his HEI by the firewall. Everything works, and it fit right in.

DaHateTank · 10-05-2002, 10:52 PM

Interesting. Ive got a 396 in my Blazer, and I moved the crossmembers forward an inch.

There's no way, I could put an HEI in my truck. I have to remove the rotor, to get the distributor outta the motor....

short Moroso valvecovers nearly hit the firewall.

used the small block mounts, had to trim the small block fan shroud. Moved the clutch bellcrank to line up with pivot ball hole in BBC.

used Hedman engine swap headers, fit pretty well, after a couple of dents, and a small (1/4 inch deep) notch in the framerail.

HTH

-Marty

10-03-2002, 05:29 PM	#1
71blksuper4x4 SWB 4x4 Collector Join Date: Jun 2001 Location: Osage City, KS Posts: 5,151	Installing a 454 in my 71 4x4 I know you guys have heard and answered this question before, but what are the procedures for dropping in a big block in my 71 swb 4x4? I know one idea is to put a 2-3 inch body lift, but I already have it lifted 5 1/2 sus. so I didn't want to do that. I have also heard that you can take a 73 crossmember and scoot it up on the frame, and take 73 big block mounts and somehow fit those in to keep from notching the firewall. I really do not want to cut the firewall on a cheyenne super, so if anyone out there can get me some tips, I would sure appreciate it. (I have already found the 73 components, just need to hear if it will work or not) __________________ TREVOR 1970 CST swb 4x4 (speedwarning,cruise,tilt,tach,8track, original red shoulder belts,tow hooks) 1972 Jimmy (soon to be Hickey cloned) 1971 Cheyenne Super 4x4 swb (tilt,tach,buckets, original blue shoulder belts,am/fm,cruise,tow hooks, dealer 8 track) 1972 Cheyenne Super K20 4x4 Custom Camper (tilt, tach, am/fm, tow hooks, bed toolbox, aux gas tank 1972 Cheyenne Super Crew Cab K30 4x4 Duramax, Allison, np205, buckets, tow hooks (CURRENT PROJECT) http://67-72chevytrucks.com/vboard/s...d.php?t=624819 1989 V3500 Crew Cab (454tbi, NV4500, np205) 1970 Chevelle SS (LS5 454,th400,8track,buckets,tach) :2004 Jeep Wrangler Rubicon (daily driver) WTB: 1968-70 Cruise Control Lever

10-03-2002, 11:39 PM	#2
BLAZERMAN Currently Blazerless Join Date: Apr 2000 Location: St. Joseph Mo. Posts: 4,826	Sent this info to Yukon Jack awhile back and he posted it on the message board. I dont know anyone who has done it but it looks like a good alternative to beating on your firewall or having to use a body lift. If you try it be sure to keep us posted. http://67-72chevytrucks.com/vboard/s...threadid=24915 __________________ 1972 C/30 133" W.B. C&C 1970 GMC 3500 157" W.B. single wheel C&C

10-04-2002, 04:46 PM	#4
breeh Recovering 67-72 Addict Join Date: Oct 2000 Location: North Bend, WA Posts: 1,788	I just put a 427 in mine. I also added a 700R4 so I knew that I was going to be moving crossmembers. I moved the engine crossmember 2 inches forward. I also used high performance polyurethane motor mounts. The motor fits in there perfect with no interference problems. It sits in the right position so that a factory BB fan shroud also fits well. BTW, I am using a short water pump setup. Good Luck __________________ 68 Short Fleet 4x4; 427; BTO Level 3 700R4; NP205; Dana 60 front and rear; 4" lift with 35's; Disc brakes; AGR variable ratio steering; factory bucket seats; factory tach and tilt. "Friends call me cruzer cuz I like fast cars and fast women"

10-04-2002, 12:42 AM	#3
Truck Hippy Registered User Join Date: Aug 2002 Location: Hickory, NC. Posts: 776	Hey. I did this swap several years ago with a 72' 4x4. I droped in a 454 and it was no sweat, The truck was a automatic (350 turbo) and i didn't have to cut or move anything. I had an HEI in it with no firewall problems. If i remember right, the only thing i did was on the drivers side there are 3 small bolts that come through from the inside of the cab that hold the gas pedel to the firewall. Make sure those don't stick out very far because that is where the valve cover lip will be and motor movement will cause it to hit. Also on the pass side firewall the valve cover lip is very close to. I don't remember if it would rub or not but i did put a small dent just to make sure it didn't rub. This was an A/C truck and every thing worked out fine. Just take it nice and slow and it should work out ok. E-mail me if you need any more info.

10-04-2002, 11:08 PM	#5
MJN Registered User Join Date: Feb 2000 Location: Maquoketa, Ia/ Orr, Mn Posts: 2,979	My brother just put a 454 in his '72 GMC and the best way he was told was to move the engine crossmember ahead one inch. Then everthing else move forward too of course but thats all you have to do. then all the original linkage will lineup and be useable. He can also put both his hands behind his HEI by the firewall. Everything works, and it fit right in.

10-05-2002, 10:52 PM	#6
DaHateTank Registered User Join Date: Aug 2002 Location: Iowa Posts: 119	Interesting. Ive got a 396 in my Blazer, and I moved the crossmembers forward an inch. There's no way, I could put an HEI in my truck. I have to remove the rotor, to get the distributor outta the motor.... short Moroso valvecovers nearly hit the firewall. used the small block mounts, had to trim the small block fan shroud. Moved the clutch bellcrank to line up with pivot ball hole in BBC. used Hedman engine swap headers, fit pretty well, after a couple of dents, and a small (1/4 inch deep) notch in the framerail. HTH -Marty



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