BB Tower Holes don't line up - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Orence1 · 09-02-2002, 09:31 PM

Pulled the 350 out of my 72 Cheyenne a while back. Got some BB 72 towers from Desert Rat earlier in the year. Just about done cleaning and painting the engine compartment. Set the towers down to discover that the two holes on the top of the frame rail line up great as does the crossmember hole on the firewall side. The hole in the tower at the front (radiator side) does not line up. I was very suprise as I assumed that the factory would have drilled the necessary holes for this engine option (402). I am just wondering if anybody can shed any light on this situation. Any help appreciated.
Larry

1-PU70 · 09-02-2002, 09:37 PM

When I did mine 72 mounts in a 70 C/10 with 307 I had to drill the front holes. The mounts came from a 72 C/20 and there was a bolt in the front hole. Maybe 3/4 tons are different.

71402BB · 09-02-2002, 09:49 PM

I also remember having to drill the front hole when I went from a 250 I-6 to my 402BB.

09-02-2002, 09:31 PM	#1
Orence1 Registered User Join Date: Jan 2000 Location: Bothell, WA Posts: 548	BB Tower Holes don't line up Pulled the 350 out of my 72 Cheyenne a while back. Got some BB 72 towers from Desert Rat earlier in the year. Just about done cleaning and painting the engine compartment. Set the towers down to discover that the two holes on the top of the frame rail line up great as does the crossmember hole on the firewall side. The hole in the tower at the front (radiator side) does not line up. I was very suprise as I assumed that the factory would have drilled the necessary holes for this engine option (402). I am just wondering if anybody can shed any light on this situation. Any help appreciated. Larry Attached Images

09-02-2002, 09:37 PM	#2
1-PU70 Registered User Join Date: Apr 2000 Location: Bradenton, FL Posts: 1,036	When I did mine 72 mounts in a 70 C/10 with 307 I had to drill the front holes. The mounts came from a 72 C/20 and there was a bolt in the front hole. Maybe 3/4 tons are different. __________________ 1970 CST/10 402,700R4,3:73 posi,AC,PS,PB,TLT,PW,Buckets with heaters

09-02-2002, 09:49 PM	#3
71402BB now thats a true COON DOG Join Date: Nov 2000 Location: Franconia, NH Posts: 1,977	I also remember having to drill the front hole when I went from a 250 I-6 to my 402BB. __________________ current project 67 402BB stout th350 3.08's with a locker. Plan on tubs 18.5's out back! (thanks Burnsman!) 71 SWB Stepside, was a 250, now is a 402 Big Block with 4 speed and 3.73's ( was crushed by a tree, bed sold, motor pulled) was my first truck!... oh well... 72 LWB 4x4 350 4-speed 3.08's posi wearing army olive drab green (SOLD!) 68 BURB 50TH LOOKALIKE work in progress, soon to have 250-I6 with a 3-speed on the tree 4.11's and posi ( currently sitting in back yard tarped awaiting time, $$$, and lots of love!) 67 1 TON- work truck 396 sm 420 4-speed, flat bed 4.57 gears "big red" (my first landscape truck, very rusty and crusty! but still gets the job done when needed!)



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