Big Block Motor Mounts on the cheap.

[Tx Firefighter]

All right fellers, some folks have requested that I do an FAQ on this.

Here's the skinny,

There are 2 types of factory big block mount setups for 67-72 trucks. The first type is 68-72 and real common. The other type is 72 only.

The 68-71 type use a real cheap frame stand. Usually available on the parts board for 60-100 bucks per pair. The downside to these is the rubber motor mount part costs big bucks, real big bucks.

The 72 setup will cost you at least double to buy, but the rubber mount parts are real cheap to buy.

It's all a trade off you see?

Here's what I have done and am currently doing on my 70 truck.

First, buy a set of the early (68-71 type) frame stands from the parts board or ebay or whatever your favorite is. Then, buy a pair of 67-72 truck small block motor mount rubbers. These small block rubbers should cost about 15 to 20 bucks per pair, which is like a zillion times cheaper than big block rubber mounts. Available in any store too.

Install the big block frame stands into the frame holes and bolt the small block rubber mounts to the big block engine. They bolt right on. Now, you need two real big burly washers. I use harmonic balancer bolt washers. They have the little hole in the middle, yet are big and thick. You need these because the bolt holes in the big block stands are very large and the bolt in the small block rubbers is small.

Now, drop the engine in and bolt it down.

You have like 50-100 total in your BBC mounts now, instead of 200 plus like normal. And, if you ever need new motor mounts, you will only be out 15 or 20 bucks to buy the generic SBC ones.

Yes, I have done this several times before. It works and works well.

Also, you must run the big block frame stands with a big block, there's no getting off cheaper by substituting small block or inline 6 frame stands. I have set the engine down onto small block stands before, and tried for months to find a header or exhaust manifold that would clear. The BBC mount stands have a dish in them for manifold clearance that SBC ones don't.

First two pics are a 68-71 big block frame stand. Note the dish for manifold clearance and the big hole in the middle where the washer must go when using normal small block rubber mounts.

[Tx Firefighter]

Here's a 67-72 small block engine mount bolted onto the big block engine.

It's a straight bolt on, no mods or strong words necessary.

[Tx Firefighter]

Here's the engine, with small block mounts bolted down to the big block frame stands.

Notice the manifold clearance offered by the droop in the big block stands that is necessary and not afforded by the small block frame stands.

Remember to use the big thick washers on the motor mount bolt so it will not pull through the big holes in the frame stand.

Doing it this way will save you probably better than a 100 bucks and make it so you can buy mounts real easy down the road, rather than searching for hard to find and expensive 68-71 big block rubber mounts.

[Big Bad 1972 Blazer]

Thanks for the tip.

Couple quick questions though....it looks like the truck in the posted pictures is a 2wd. Would the same mods work on a 4x4? I'm in the process of converting my '72 4x4 Blazer to a 454 and am looking for the best/easiest way to mount the BB. I'm still building up the motor and haven't begun to worry about mounting it yet, so having never seen the BB frame mounts, is the only difference with the SB frame mounts the clearance for the for the exhaust manifold. I'm going to be using headers (Hedmans to be exact) on my truck and am wondering if the use of headers would eliminate this problem and allow me to use my existing engine mounts.

Thanks again.

[magic402]

What Ive done on the 4x4 is left the trans/tc in place and moved the engine cradle foward , I thought the next set of holes lined up in the frame. hooking up an A/T is easy, but with the M/T I had to redo the position of the bellcrank. I think used a different fan shroud too, the BB W/P is higher? mike