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SAAC Forum => SAAC Forum Discussion Area => Topic started by: 68stangcjfb on May 14, 2026, 07:03:42 AM

Title: Reverse 105 FE block question.
Post by: 68stangcjfb on May 14, 2026, 07:03:42 AM
Has anyone seen a reverse 105 FE engine block without the outside extra ribs on the sides 0f the skirts. Casting date looks to be October of 1973, but first digit is just about unreadable.
Title: Re: Reverse 105 FE block question.
Post by: Bigfoot on May 14, 2026, 10:51:22 AM
Do you have a picture of your block?
Title: Re: Reverse 105 FE block question.
Post by: 68stangcjfb on May 14, 2026, 01:00:02 PM
https://www.facebook.com/marketplace/item/2419495245212607/?ref=marketplace_profile&referral_code=undefined
It's a friend of mines block. For sale.
Title: Re: Reverse 105 FE block question.
Post by: Coralsnake on May 14, 2026, 02:29:09 PM
So a reverse 105 is a truck block. Its my understanding the ribs were added to extend the life of the molds
Title: Re: Reverse 105 FE block question.
Post by: shelbydoug on May 14, 2026, 04:19:57 PM
Quote from: Coralsnake on May 14, 2026, 02:29:09 PMSo a reverse 105 is a truck block. Its my understanding the ribs were added to extend the life of the molds

Yes.

The ribs appear somewhere in 1972.
Title: Re: Reverse 105 FE block question.
Post by: 68stangcjfb on May 14, 2026, 05:58:20 PM
Yes, but if you look at the pictures, the casting date has the 2 dots and what looks like a 10/18/1973 casting date but without the ribs. It also doesn't have a bushing in the distributor hole and a drain back hole in the pan rail. I thought all the around 1972 & later blocks had the ribs until I saw this one.
Title: Re: Reverse 105 FE block question.
Post by: shelbydoug on May 14, 2026, 06:57:24 PM
I would say that the casting date is wrong OR it is a 1963 casting date. A '73 block would have ribs. The molds broke and when repaired wound up with ribs. The 427 blocks have them also with 72 casting dates.

I also think that it is a 390 block, not a 428.Personally I would not consider it without an A or C scratch but I'm not well informed on the truck versions. Plus, you would not want to use that block in anything special.

People have bored those out to 4.13.

Title: Re: Reverse 105 FE block question.
Post by: pbf777 on May 14, 2026, 08:36:10 PM
Here's a good little read:

https://www.fordfe.com/what-is-a-105-block-t5869.html

Scott.
Title: Re: Reverse 105 FE block question.
Post by: 68stangcjfb on May 15, 2026, 01:42:09 PM
It's not a 1963 block. It has 3 bolt motor mounts, the extra inside web rib, the reverse 105 on front & back, the MCC casting logo & a 4.13 bore (it's an NOS block). I told him to check for the cast in "428" in the water jackets.
Title: Re: Reverse 105 FE block question.
Post by: shelbydoug on May 15, 2026, 03:12:56 PM
Quote from: 68stangcjfb on May 15, 2026, 01:42:09 PMIt's not a 1963 block. It has 3 bolt motor mounts, the extra inside web rib, the reverse 105 on front & back, & a 4.13 bore (it's an NOS block). I told him to check for the cast in "428" in the water jackets.
You are looking for a possible explanation. It is more likely that the casting date is incorrect then the ribs being wrong.

Not all 428's have a visible number from the water jackets. That's a 50/50 proposition. As many don't as many do.
Title: Re: Reverse 105 FE block question.
Post by: pbf777 on May 15, 2026, 06:06:16 PM
    But the "reverse 105" castings weren't created until 1972.   :)

    Scott.
Title: Re: Reverse 105 FE block question.
Post by: shelbydoug on May 16, 2026, 08:59:50 AM
Quote from: pbf777 on May 15, 2026, 06:06:16 PMBut the "reverse 105" castings weren't created until 1972.   :)

    Scott.

Just when you thought it was "safe to go back in the water", another FE enigma.

Why am I not shocked? :o
Title: Re: Reverse 105 FE block question.
Post by: 68stangcjfb on May 18, 2026, 05:56:03 AM
Quote from: Bigfoot on May 14, 2026, 10:51:22 AMDo you have a picture of your block?

Added pic to 1st post.
Title: Re: Reverse 105 FE block question.
Post by: TA Coupe on May 18, 2026, 09:10:04 AM
Quote from: 68stangcjfb on May 18, 2026, 05:56:03 AM
Quote from: Bigfoot on May 14, 2026, 10:51:22 AMDo you have a picture of your block?

Added pic to 1st post.

 I enhanced your new picture a little bit. Tap or click where it says L-S block. Jpg for full size.

     Roy
Title: Re: Reverse 105 FE block question.
Post by: 68stangcjfb on May 18, 2026, 09:54:24 AM
Quote from: TA Coupe on May 18, 2026, 09:10:04 AM
Quote from: 68stangcjfb on May 18, 2026, 05:56:03 AM
Quote from: Bigfoot on May 14, 2026, 10:51:22 AMDo you have a picture of your block?

Added pic to 1st post.

 I enhanced your new picture a little bit. Tap or click where it says L-S block. Jpg for full size.

     Roy

Thank you. :D