New LS for my 72 blazer
 

Does anyone know what I will need to change on the motor mounts when I install the new LS motor? Or will the stock ones work?

Re: New LS for my 72 blazer
 

You need a different crossmember for the engine to fit. The stock one is too narrow. There are a couple of companies making them. I used a Tilden on mine. Depending on the transmission it will pretty much be a bolt in job. I used a 4l80e and had to elongate the th400 frame holes to slide the crossmember forward slightly. If you use a 4l60 you likely won’t have to do that and it will bolt right in. Also be sure the pan will fit. I used a Holley swap pan and it fits fine. The Tilden comes with motor mounts included along with bolts. The other thing I like about it is you don’t have to move your brake lines.

Re: New LS for my 72 blazer
 

Subbed.

Re: New LS for my 72 blazer
 

Thanks for the info on the crossmember. I am using a 4l60e. If I can figure out how to get pictures on the site I will show my progress. I have rust free 72 all stock. It should be a good build.

Re: New LS for my 72 blazer
 

Welcome Batman!!! Oh I get it now. 4X4. Duh

Re: New LS for my 72 blazer
 

Yeah move the engine forward with the crossmember and you will be golden. You won’t have to change much with that method. If you buy the adapter you can bolt the 205 tcase to the 4l60 and back into the stock location and it will look stock from the cab. No one will even know you have an overdrive. I considered the 60 or 70e but I have a stout ls3 and wanted the Tranny to last a long time. The 80e pushed the engine pretty far forward though. I have to run electric fans and I have a Wagner serpentine drive. I believe the 60e is about 4 or 5 inches shorter.

Re: New LS for my 72 blazer
 

Your Blazer looks nice, I found two different crossmembers one is made here in AZ it appears. I will find out tomorrow.

Re: New LS for my 72 blazer
 

Here’s a couple more recent pics. I added a 3” lift. I also noticed I used the original holes for the th350 location. Its been a bit since I put it in. There’s a lot of adjustability with the Tilden crossmember. The others out there don’t use the original frame holes. You have to drill new ones. I wasn’t a fan of that and if you ever change transmissions you have to redrill.

Below is the crossmember I used and it’s on sale:

http://tildenmotorsports.com/63-72-g...ssmembers.html

Re: New LS for my 72 blazer
 

That really looks nice. I found a place here in the Phoenix area Dirty Dingo Motorsport that makes a crossmember. I spoke with there sales dept today and yes there is some drilling required with there product. That seems to be the only downside. Good thing is they are local and they work with my engine builder on other projects. I will keep you informed on how I like the product. I am picking up the crossmember tomorrow.

Re: New LS for my 72 blazer
 

Thanks for the compliment. It’s definitely a labor of love. I can’t wait to drive it again.

I have the DD crossmember. I bought it a few years before the swap. I’m pretty sure you have to reroute your brake lines and it doesn’t have any adjustment. It has the plus of a removable center section but I prefer the Tilden's adjustability.

I think that your advice is good you have done the work, the Tilden is the winner. It is also $100 cheaper.
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Re: New LS for my 72 blazer
 

Either one should work but I was worried about drilling so it was a preference on my part. I threw away some money buying both but I figure I can sell it when I get time to box it up. Post up some pics with what you go with. There aren’t a lot of threads for the 4x4 swap so it’s always nice to have a reference. I like your blazer that’s a good color.

Re: New LS for my 72 blazer
 

I am thinking about putting a ls in my Blazer next year. Since you are in the process of doing this have you considered putting together a parts list and posting it in your thread. I thought a lift kit was required to convert to a LS and I do not want to put a lift on my Blazer.

Re: New LS for my 72 blazer
 

I am in my infant stage of this swap, from what I I have read an been told a lift is not required but it is recommended due to having to change the crossmember and it is lower than the original. There may be clearance issues.

Re: New LS for my 72 blazer
 

Mine required the lift. It was really close to the pumpkin.

Re: New LS for my 72 blazer
 

Wow - thanks for this info. I’d like to go with the pac fab crossmember but don’t want to lift my blazer. Didn’t realize it would be that close. They do recommend at least 2” lift right?

Re: New LS for my 72 blazer
 

I believe they said 2.5” is minimum. The DD cross-member is said to not require a lift but I would make sure you are ready to lift it. The cross-member is much wider than stock due to the LS block. It just requires much more room. Also when I lifted mine 3” it looks more like 6” The original springs were pretty saggy.

Re: New LS for my 72 blazer
 

Did you have to do any fab work to move the motor forward? Or does the tilden crossmember allow you to do so without any fab work

Re: New LS for my 72 blazer
 

Sub'ing onto this thread as I am doing a swap into a 4x4 as well. Spoke with Tilden yesterday and am sold on their product (plus reading Blazerowner's experience and others). They did say that I may have to move everything forward an inch to get the motor to clear the firewall. Some do, some don't.

I am putting in the 4L65E that came with my 6.0. I spoke with Advanced Adapters and ordered their kit. I will take it to a local transmission shop to have the new output shaft put in. Anything else I should do while they have it opened up other than check it over?

Just got done rebuilding my NP205 with the ORD kit and am hoping to leave it in the stock location.

Starting to think ahead to the wiring part of the project. Blazerowner, are you still thinking about the Holley Terminator Max? Care to share your thoughts on going that route?

Re: New LS for my 72 blazer
 

If you have the transmission opened up, you might as well rebuild it and do all the updates. Not sure about the 65e, but the weak link in the 60e is the sunshell. A good upgrade is a heavy duty sunshell called "The Beast".

Re: New LS for my 72 blazer
 

I have an older Holley kit. I’ve started wiring it but I bought a new house and it’s been on the back burner. Im also having a shop built so it may be a few months before I can get back to it. The Holley kit I bought has a dominator ECU which to me was a big selling point at the time. Of course the new terminator kit is much cheaper. I think I paid 3 grand for the kit I have. I do know I’m impressed with Holley”s quality. All top notch and fairly easy to understand. The 4l60 will move your engine forward a bit. I have a ton of room with 4l80. I think yours will be fine if not perfect. I would avoid moving the tcase as this creates more work to your drive-lines, and making new holes for tcase mount and transmission crossmember. Even the tcase shifter will have to be reworked.

Re: New LS for my 72 blazer
 

Subscribed! I got a 6.0 and 4l80 to put into my 72 k5.

Re: New LS for my 72 blazer
 

Thanks Hemi! My AA kit arrived today so I am taking the trans to the shop this week to get the shop to get the output shaft installed and will talk to them about some upgrades. I have a 4L60e in my 2004 Suburban and had it rebuilt with a new sunshell, corvette servo, and a few other things. I know the 4l65 had a few upgrades from the 60 but I think these are still weak points.

Blazerowner, the more I read about the Terminator X, the more I think I will give it a try. I get torn between really enjoying the process and wanting to try to rework my harness and getting this thing running and moving onto other aspects of the truck. The only downside I can see to the Holley system is no cruise control option which I wanted but can live without. Other than that I am too much of a newbie to worry about things like MAF versus Speed Density, etc. I think a plug and play solution will work better for me right now.

Re: New LS for my 72 blazer
 

For me it was the ability to tune it myself. I didn’t want to have to deal with taking it to a shop every time I changed something. Check out Dakota digital. They have cruise control options for LS engines. Their gauge kit is also plug and play with the Holley kit.

Re: New LS for my 72 blazer
 

Will check it out. I guess it must operate separately from the ECU.

What did you use for gauges?