Sbc to bbc problems. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

bd blk 12v · 05-11-2013, 07:23 PM

Hello guys. I'm a long time lurker almost first time poster. I need some help. I have been searching and haven't had the best of luck. I have a 69 cst odd ball year I'm finding out. It was a 350 350 truck. The block was cracked on the starter mounting bolts. A friend had an l34 396 out of a chevelle and I bought it. I changed the cam and bought the 73-87 frame mounts. I bought some moroso solid motor mounts from him. They are part number 710-62630k. I bought Harland sharp roller rockers and ebay fabricated bbc valve covers. We installed the engine and both valve covers are against the fire wall. My buddy and I installed the trans and the crossmember and linkage is off too far back about an inch and a half. What would be the correct way to repair this? Is the mounts not correct? What should I buy? I don't want to cut and drill if I don't have to. Thanks guys I have a long water pump on the engine also.
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**Daubs** · 05-11-2013, 07:39 PM

I'm sure someone here will have more accurate information than me. But that big block should fit with proper motor mounts. My Dad had a 70's c-20 with the big block. Straight from factory. Something is not right with your motor mounts(?)

bd blk 12v · 05-11-2013, 07:41 PM

Thanks for the reply. I'm at a loss I don't know what I need to do to resolve the issue.
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Mike C · 05-11-2013, 08:25 PM

67-71 had different frame stands and mounts than any other years. 72 had it's own. 73-87 trucks are very similar front suspension wise, but driveline placement in relation to the cab is different. Most big block conversions into 4x4 trucks requires a body lift or firewall mods. The bolt in answer is to buy correct big block mounts.

Prematuregrey · 05-11-2013, 08:33 PM

Not much help as I don't know which mounts were used, but the BB in my K20 has no room between the valve covers and firewall. It was the first thing I noticed when I popped the hood. It doesn't interfere with anything but it's close and there has been no firewall mods. I'd say research on the correct mounts you would need or make some custom ones.

bd blk 12v · 05-11-2013, 08:35 PM

The truck is a 2wd. Thanks for the help.
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biohazardbill · 05-11-2013, 08:45 PM

Are the mounts in the forward holes on the frame?
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bd blk 12v · 05-11-2013, 08:50 PM

Yes sir they are in the forward most holes in the frame. I have headers on it and they fit perfect but nothing else does.
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biohazardbill · 05-11-2013, 08:54 PM

When I put my bbc in the 67 I used the cpp mounts in the forward holes with the tall valve covers. Running Chevelle mid length headers. I can fit my fingers between the valve covers and the firewall. How low is your trans sitting? Maybe tilted to far back?
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bd blk 12v · 05-11-2013, 09:01 PM

I will have to look at the transmission. I have the transmission mounted to the engine and the crossmember under the trans. I have an energy suspension trans mount on it but it looks like the engine and trans needs to move forward.
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biohazardbill · 05-11-2013, 09:04 PM

Pics would probably help.
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bd blk 12v · 05-11-2013, 09:08 PM

I will get some tomorrow its in the storage with no lights. Thanks for the help.
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**too much stuff** · 05-11-2013, 09:32 PM

Quote:

Originally Posted by biohazardbill

Are the mounts in the forward holes on the frame?
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It sounds like you are in the rear holes. I think the 73 mounts will work, but you will have to move them forward to the other set of holes and i think you will need to drill some new holes for the lower ones.

bd blk 12v · 05-11-2013, 09:49 PM

Too much stuff the 73-87 stands are in the front holes of the frame. They are not in the rear holes.
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**Tom Vogel** · 05-11-2013, 09:57 PM

I put a BB in mine. I used the 72 stand and mounts and everything is fine. Tall fabricated valve covers and all. Oh yea, I have the long water pump AND a big Procharger, and it all clears my electric fans.
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VA72C10 · 05-11-2013, 10:18 PM

73-87 mounts do not fit the same...you have to move them further forward. Either get the 72 mounts or move the 73-87 mounts approx 1 1/2" forward.

bd blk 12v · 05-11-2013, 11:00 PM

Ok if I move the mounts forward will I have clearance from the wp to the radiator. I have an electric fan I was goin touse as a puller. I measured with the fan installed I have about 3/4 of an inch. What if I buy the performance online tubular mounts? Is this a good idea and delete the 73-87 stands?
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VA72C10 · 05-11-2013, 11:21 PM

Not sure how it's that close to the radiator/fan and also hitting the firewall...I had tons of room with the 72 engine stands at the front...it's tight at the firewall but there was plenty of room for a factory fan which is a lot bigger than an electric fan

...unless you have both (electric fan and a stock fan) then I'd use the electric fan as a pusher if possible...

Robznob11 · 05-11-2013, 11:39 PM

Quote:

Originally Posted by bd blk 12v

Ok if I move the mounts forward will I have clearance from the wp to the radiator. I have an electric fan I was goin touse as a puller. I measured with the fan installed I have about 3/4 of an inch. What if I buy the performance online tubular mounts? Is this a good idea and delete the 73-87 stands?
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I dont see why you wouldn't these trucks came with bbc so there should b e plenty of room, also that car motor should have a short wp. Id move the stands forward 1 1/2" it is easy to drill a few holes if you have to i did to put the ls in! Used the same mounts only i went further back lol!
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Shyguy · 05-12-2013, 12:25 AM

When we put the '74 454 in my '69 frame we used the motor mounts and frame stands from the '74. We did have to move the motor forward and drill new holes in the frame and the cradle.

The reason we went with the stuff from the '74 was they allowed room for the hooker headers I had and allowed plenty of room for the clutch Z bar.

05-11-2013, 07:23 PM	#1
bd blk 12v Registered User Join Date: Oct 2009 Location: hobbs nm Posts: 29	Sbc to bbc problems. Hello guys. I'm a long time lurker almost first time poster. I need some help. I have been searching and haven't had the best of luck. I have a 69 cst odd ball year I'm finding out. It was a 350 350 truck. The block was cracked on the starter mounting bolts. A friend had an l34 396 out of a chevelle and I bought it. I changed the cam and bought the 73-87 frame mounts. I bought some moroso solid motor mounts from him. They are part number 710-62630k. I bought Harland sharp roller rockers and ebay fabricated bbc valve covers. We installed the engine and both valve covers are against the fire wall. My buddy and I installed the trans and the crossmember and linkage is off too far back about an inch and a half. What would be the correct way to repair this? Is the mounts not correct? What should I buy? I don't want to cut and drill if I don't have to. Thanks guys I have a long water pump on the engine also. Posted via Mobile Device

05-11-2013, 07:39 PM	#2
Daubs Registered User Join Date: Jan 2005 Location: Eastern Nebraska Posts: 613	Re: Sbc to bbc problems. I'm sure someone here will have more accurate information than me. But that big block should fit with proper motor mounts. My Dad had a 70's c-20 with the big block. Straight from factory. Something is not right with your motor mounts(?) __________________ '72 Chevy K-20 Crate 350, SM465, 4.10's

05-11-2013, 07:41 PM	#3
bd blk 12v Registered User Join Date: Oct 2009 Location: hobbs nm Posts: 29	Re: Sbc to bbc problems. Thanks for the reply. I'm at a loss I don't know what I need to do to resolve the issue. Posted via Mobile Device

05-11-2013, 08:25 PM	#4
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,727	Re: Sbc to bbc problems. 67-71 had different frame stands and mounts than any other years. 72 had it's own. 73-87 trucks are very similar front suspension wise, but driveline placement in relation to the cab is different. Most big block conversions into 4x4 trucks requires a body lift or firewall mods. The bolt in answer is to buy correct big block mounts. __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax

05-11-2013, 08:33 PM	#5
Prematuregrey Registered User Join Date: Apr 2013 Location: Austin Texas Posts: 111	Re: Sbc to bbc problems. Not much help as I don't know which mounts were used, but the BB in my K20 has no room between the valve covers and firewall. It was the first thing I noticed when I popped the hood. It doesn't interfere with anything but it's close and there has been no firewall mods. I'd say research on the correct mounts you would need or make some custom ones. __________________ Owner: Times Are Tough Toys 92 4 Runner (Joyce, long story from my time in Africa) Lotsa stuff, just about finished dumping money into it. 89 Mercedes 560 SEL, Merdle. Wrecked 71 Chevy K20, Clifford, BB and 1 Tons

05-11-2013, 08:35 PM	#6
bd blk 12v Registered User Join Date: Oct 2009 Location: hobbs nm Posts: 29	Re: Sbc to bbc problems. The truck is a 2wd. Thanks for the help. Posted via Mobile Device

05-11-2013, 08:45 PM	#7
biohazardbill Registered User Join Date: Jan 2010 Location: Forsyth, Ga Posts: 1,012	Re: Sbc to bbc problems. Are the mounts in the forward holes on the frame? Posted via Mobile Device

05-11-2013, 08:50 PM	#8
bd blk 12v Registered User Join Date: Oct 2009 Location: hobbs nm Posts: 29	Re: Sbc to bbc problems. Yes sir they are in the forward most holes in the frame. I have headers on it and they fit perfect but nothing else does. Posted via Mobile Device

05-11-2013, 08:54 PM	#9
biohazardbill Registered User Join Date: Jan 2010 Location: Forsyth, Ga Posts: 1,012	Re: Sbc to bbc problems. When I put my bbc in the 67 I used the cpp mounts in the forward holes with the tall valve covers. Running Chevelle mid length headers. I can fit my fingers between the valve covers and the firewall. How low is your trans sitting? Maybe tilted to far back? Posted via Mobile Device

05-11-2013, 09:01 PM	#10
bd blk 12v Registered User Join Date: Oct 2009 Location: hobbs nm Posts: 29	Re: Sbc to bbc problems. I will have to look at the transmission. I have the transmission mounted to the engine and the crossmember under the trans. I have an energy suspension trans mount on it but it looks like the engine and trans needs to move forward. Posted via Mobile Device

05-11-2013, 09:04 PM	#11
biohazardbill Registered User Join Date: Jan 2010 Location: Forsyth, Ga Posts: 1,012	Re: Sbc to bbc problems. Pics would probably help. Posted via Mobile Device

05-11-2013, 09:08 PM	#12
bd blk 12v Registered User Join Date: Oct 2009 Location: hobbs nm Posts: 29	Re: Sbc to bbc problems. I will get some tomorrow its in the storage with no lights. Thanks for the help. Posted via Mobile Device

05-11-2013, 09:49 PM	#14
bd blk 12v Registered User Join Date: Oct 2009 Location: hobbs nm Posts: 29	Re: Sbc to bbc problems. Too much stuff the 73-87 stands are in the front holes of the frame. They are not in the rear holes. Posted via Mobile Device

05-11-2013, 09:57 PM	#15
Tom Vogel 2WD Jimmy Join Date: Mar 2005 Location: Davis County, Utah Posts: 2,565	Re: Sbc to bbc problems. I put a BB in mine. I used the 72 stand and mounts and everything is fine. Tall fabricated valve covers and all. Oh yea, I have the long water pump AND a big Procharger, and it all clears my electric fans. Posted via Mobile Device Posted via Mobile Device Attached Images

05-11-2013, 10:18 PM	#16
VA72C10 VA72C10 Join Date: Mar 2008 Location: Midlothian, VA Posts: 25,267	Re: Sbc to bbc problems. 73-87 mounts do not fit the same...you have to move them further forward. Either get the 72 mounts or move the 73-87 mounts approx 1 1/2" forward. __________________ Looking for a 67-72 swb or blazer project in or around VA.



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05-11-2013, 11:00 PM	#17
bd blk 12v Registered User Join Date: Oct 2009 Location: hobbs nm Posts: 29	Re: Sbc to bbc problems. Ok if I move the mounts forward will I have clearance from the wp to the radiator. I have an electric fan I was goin touse as a puller. I measured with the fan installed I have about 3/4 of an inch. What if I buy the performance online tubular mounts? Is this a good idea and delete the 73-87 stands? Posted via Mobile Device

05-11-2013, 11:21 PM	#18
VA72C10 VA72C10 Join Date: Mar 2008 Location: Midlothian, VA Posts: 25,267	Re: Sbc to bbc problems. Not sure how it's that close to the radiator/fan and also hitting the firewall...I had tons of room with the 72 engine stands at the front...it's tight at the firewall but there was plenty of room for a factory fan which is a lot bigger than an electric fan ...unless you have both (electric fan and a stock fan) then I'd use the electric fan as a pusher if possible... __________________ Looking for a 67-72 swb or blazer project in or around VA.

05-12-2013, 12:25 AM	#20
Shyguy Junior Member Join Date: Dec 2006 Location: Southeast Missouri Posts: 2,436	Re: Sbc to bbc problems. When we put the '74 454 in my '69 frame we used the motor mounts and frame stands from the '74. We did have to move the motor forward and drill new holes in the frame and the cradle. The reason we went with the stuff from the '74 was they allowed room for the hooker headers I had and allowed plenty of room for the clutch Z bar. __________________ '67 Chevy C-20 short stepper - build complete, 454/SM-465. '75 C-30 Single Cab DRW-350 small block/NP-435. '77 GMC-6500 Dump Truck, 427 Tall Deck. '92 GMC K-3500 Duallie, 454/4L80E.

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