I'm still giving these a 5 star even though they don't exactly fit my application. The #1 primary hits the head stud and the #4 hits the OEM engine mount. I have a 1970 GMC 1500. LM7 block, LS1 heads with head studs. I'm using the SBC style mounts.
You may not run into this, but do be aware it may not fit every application (don't be afraid of the hammer if it doesn't fit!).
They fit perfect in my 88 Ls brougham caprice classic with no problems . Didn’t have to modify or adjust anything . Bolted up fine and fit in there perfect & yes it’s they’re on my LS motor ( did a LS swap )
Fit my 72 c10 6.0 LS swap very well. These are easily the best bang for your buck headers.
I bought these for a 1970 c10 with a gen 3 5.3 ls and 4l60e trans swap. They fit great. Installation was easy, the don't come in contact with the frame or trans or anything and aren't overly priced either.
I purchased these in person in the shop today, I was a bit nervous about their fit because so many big name places claim theirs will fit 73-87 C10s but many do not fit at all. These are a perfect fit and require zero cutting of the frame or crossmember. The only modification these needed to work on my truck is a simple one. Cut the passenger side transmission ear off with a grinder. To be fair this is likely because I'm using an early style 4L80E. I couldnt be happier with this product. Well done, Speed Engineering. Just so we're clear I'm in no way paid to leave this review and I do not work for/with Speed Engineering. I'm just a happy customer who is very glad to pass along the good news to fellow 73-87 C10 owners. Now theres more options than just Trail Blazer SS headers, which can be very expensive.