Motor Mounts

[GRYGOSE]

What have you guys used for big block swaps. i bought the block portion from summit and when i got them in the mail i knew they were wrong. what have you all done. Truck is a 72 motor is a 402

[Shyguy]

Well, we used a set of stock big block mounts from a '73 C-20 to put a big block in my '71C-10.

[GRYGOSE]

OE is way off the charts in price. anyone have a aftermarket suggestion ?

[junkyardjohn]

I DON'T HAVE ANY IDEA ON YOUR BUDGET BUT YOU CAN MOST ALWAYS FIND A SET OF 72 ONLY BB STANDS FOR UNDER $200. THEN YOU CAN USE ANY BB CLAMSHELL TYPE MOUNTS UP TO AT LEAST 86. WITH THIS ECONOMY BEING IN THE SH!TTER LIKE IT IS, YOU CAN PROBABLY FIND EM FOR HALF THAT. INVEST $25 FOR A PAID SUBCRIPTION & THEN PUT A WTB ADD ON THE PARTS BOARD. WELL WORTH THE $ & IT'LL COME BACK TO YOU RIGHT AWAY. JOHN

[raycow]

Unless you are doing a stock resto, use the 73-up mounts. Their only downside is that you have to drill a couple of new holes in the frame. For the difference in price, it is time well spent.

Ray

[junkyardjohn]

IT'S A LITTLE MORE THAN THAT RAY. IVE DONE IT. HONEST. 73 UP BB TOWERS ARE ABOUT AN INCH TALLER THAN 72 BB MOUNTS WHEN OUT IN A PRE 72 TRUCK THAT HASN'T BEEN CONVERTED TO A 73 UP CROSSMEMBER ASSY. (THIS ISN'T SOMETHING I'VE HEARD, OR READ, OR HAD A FREIND THAT SAID IT WOULD WORK). (THIS IS FROM MY OWN PERSONAL EXPERIANCE) IF IT HAS BEEN (CROSSMEMBER CONVERSION) CONVERTED, IT'S A PRETTY SIMPLE BOLT ON AFFAIR. YOU CAN MAKE THEM WORK BUT IF YOU BOLT THE BOTTOM SIDE IN.. THE TOP WILL BE ABOUT AN INCH HIGHER THAN THE FRAME RAIL. YOU CAN OVERCOME THIS BY PUTTING A SPACER ON TOP OF THE FRAIMRAIL BETWEEN THE FRAME STAND. THEN YOU'RE BB SETS AN INCH TOO HIGH & THE GEOMETRY ISN'T CORRECT. OR YOU CAN HEAT & BEND THEM TO FIT, AGAIN RUINING THE GEOMETRY, MAKING BOLTING UP THE MOTOR A REAL PAIN. 73 UP CROSSMEMBERS ARE ABOUT AN INCH DEEPER THAN 67-72 CROSSMEMBERS & THE MM TOWERS REFLECT THAT. HONEST.. I HAVE SEVERAL SETS OF EACH STYLE OUT IN MY SHOP. IF WHAT YOU CLAIM WAS INDEED CORRECT.. DON'T YOU THINK EVERYONE WOULD BE USING THE ULTRA COMMON 13 YEAR PRODUCTION, $12 73 UP TOWERS INSTEAD OF SPENDING $150 OR $200 ON 72 ONLY BB TOWERS?? OR DO YOU FIGURE EVERYONE ELSE IS JUST PLAIN STUPID & YOU ARE THE ONLY ONE THAT EVER STUMBLED ON THIS LITTLE GEM OF KNOWLEDGE??? JOHN

[Shyguy]

Originally Posted by junkyardjohn

IT'S A LITTLE MORE THAN THAT RAY. IVE DONE IT. HONEST. 73 UP BB TOWERS ARE ABOUT AN INCH TALLER THAN 72 BB MOUNTS WHEN OUT IN A PRE 72 TRUCK THAT HASN'T BEEN CONVERTED TO A 73 UP CROSSMEMBER ASSY. (THIS ISN'T SOMETHING I'VE HEARD, OR READ, OR HAD A FREIND THAT SAID IT WOULD WORK). (THIS IS FROM MY OWN PERSONAL EXPERIANCE) IF IT HAS BEEN (CROSSMEMBER CONVERSION) CONVERTED, IT'S A PRETTY SIMPLE BOLT ON AFFAIR. YOU CAN MAKE THEM WORK BUT IF YOU BOLT THE BOTTOM SIDE IN.. THE TOP WILL BE ABOUT AN INCH HIGHER THAN THE FRAME RAIL. YOU CAN OVERCOME THIS BY PUTTING A SPACER ON TOP OF THE FRAIMRAIL BETWEEN THE FRAME STAND. THEN YOU'RE BB SETS AN INCH TOO HIGH & THE GEOMETRY ISN'T CORRECT. OR YOU CAN HEAT & BEND THEM TO FIT, AGAIN RUINING THE GEOMETRY, MAKING BOLTING UP THE MOTOR A REAL PAIN. 73 UP CROSSMEMBERS ARE ABOUT AN INCH DEEPER THAN 67-72 CROSSMEMBERS & THE MM TOWERS REFLECT THAT. HONEST.. I HAVE SEVERAL SETS OF EACH STYLE OUT IN MY SHOP. IF WHAT YOU CLAIM WAS INDEED CORRECT.. DON'T YOU THINK EVERYONE WOULD BE USING THE ULTRA COMMON 13 YEAR PRODUCTION, $12 73 UP TOWERS INSTEAD OF SPENDING $150 OR $200 ON 72 ONLY BB TOWERS?? OR DO YOU FIGURE EVERYONE ELSE IS JUST PLAIN STUPID & YOU ARE THE ONLY ONE THAT EVER STUMBLED ON THIS LITTLE GEM OF KNOWLEDGE??? JOHN

Darn, I am not sure how it happened but when we used the '73 big block motor mounts to put the 454 in my '71 C-10 the engine settled into the frame nicely and mated right up to the granny 4 speed transmission. We did have to drill some holes on the top of the frame to bolt it in so the engine would be in the right position to mate to the transmission and have the proper clearance at the radiator for the fan clutch.

I crawled under the truck and checked the angle of the driveshaft and transmission and it looks good.

Now I am thinking, what the heck. How did everything work out or did it?

I may have to take a closer look and take some measurments, huh.

Edit: I just re-read your post and realized how mine worked. We did not bolt the lower motor mount to the cradle - being the kind of shade tree mechanics we are we welded it at the bottom, lol.

[clos69]

Subscribed to this as I am also going BBC 454 from a 78 to my 67 but trying to decide if I should go with 68-71 or 72 towers.

[junkyardjohn]

DANNY.. THAT EXPLANATION WASN'T MEANT FOR A GUY LIKE YOU WITH QUITE A BIT OF PRACTICAL EXPERIANCE, & I SURE WASN'T TRYING TO COME OFF AS SOME KINDA KNOW IT ALL. FAR FROM IT. IT'S JUST AGGRAVATING FOR A NEWBEE TO BE TOLD PART OF THE INFORMATION, & SPEND UNTOLD HOURS DOING WHAT THEY WERE TOLD WOULD WORK ONLY TO FIND OUT THAT IT DOESN'T WORK WITHOUT A FEW PERTINENT FACTS. BEEN THERE.. DONE THAT. AS A RESULT I HATE IT WHEN PEOPLE GIVE INNCORECT OR INCOMPLETE INFORMATION TO A GUY THAT DOESN'T KNOW ANY BETTER. INCOMPLETE ADVICE BY WAY OF SOMETHING I'VE HEARD OR READ SOMEWHERE SURE DOESN'T HELP SOMEONE SEEKING THE KNOWLEDGE THATS ALREADY CONFUSED. I TRY TO ONLY GIVE ADVICE ON THINGS THAT I HAVE PERSONALLY DONE & KNOW WORKS. JOHN

[junkyardjohn]

Originally Posted by clos69

Subscribed to this as I am also going BBC 454 from a 78 to my 67 but trying to decide if I should go with 68-71 or 72 towers.

CARLOS... IF YOU'VE GOT ACCESS TO A 78 DONOR TRUCK, THE COMPLETE FRONT END CROSSMEMBER ASSEMBLY, ALL THE WAY TO THE STEERING GEARBOX IS PURTY NEAR A BOLT ON AFFAIR. & PARTS ARE PLENTIFUL & CHEAP. JOHN

[raycow]

Junkyard is right. I had previously done a crossmember swap on the truck as part of a disc brake conversion and didn't think about it being different.

Ray

[Shyguy]

Originally Posted by junkyardjohn

DANNY.. THAT EXPLANATION WASN'T MEANT FOR A GUY LIKE YOU WITH QUITE A BIT OF PRACTICAL EXPERIANCE, & I SURE WASN'T TRYING TO COME OFF AS SOME KINDA KNOW IT ALL. FAR FROM IT. IT'S JUST AGGRAVATING FOR A NEWBEE TO BE TOLD PART OF THE INFORMATION, & SPEND UNTOLD HOURS DOING WHAT THEY WERE TOLD WOULD WORK ONLY TO FIND OUT THAT IT DOESN'T WORK WITHOUT A FEW PERTINENT FACTS. BEEN THERE.. DONE THAT. AS A RESULT I HATE IT WHEN PEOPLE GIVE INNCORECT OR INCOMPLETE INFORMATION TO A GUY THAT DOESN'T KNOW ANY BETTER. INCOMPLETE ADVICE BY WAY OF SOMETHING I'VE HEARD OR READ SOMEWHERE SURE DOESN'T HELP SOMEONE SEEKING THE KNOWLEDGE THATS ALREADY CONFUSED. I TRY TO ONLY GIVE ADVICE ON THINGS THAT I HAVE PERSONALLY DONE & KNOW WORKS. JOHN

Hey John,

You can correct me or contradict anything I write because I value and respect your vast knowledge of the these old trucks.

I started late in life working on them myself and am a novice at a lot of things. I have worked on a variety of vehicles over the years and try to apply that knowledge to these trucks, but at times I find I am at a loss.

People on this forum are great and have saved my bacon more than a few times.

I like the fact that the more experienced, knowledgeable people on here are always ready to help the newcomers.