I plan on using a set of LT1 aluminum heads and intake combo, my question is the heads have 'D' shape exhaust ports, and the SLP 1 3/4 header ports are a bit different, just wondering since the headers are still on the car, has anyone had great success with fitting them to LT1 heads, and which method of port fitting these is the best, heads to headers, or headers to heads, or a combo of both, I have gas mig that can weld both metals, the headers will be removed first prior to long block assembly, for time to port fit them prior to install, any info would be great, Jeff.

 

its pretty simple, you bolt them up and go. You don't have to change anything to use the headers. If this were an all-out race-effort engine then I would suggest port matching the headers to the heads, but on a street car you don't need to do any of that.

 

What he ^ said. And check your private message.

 

I am trying to eliminate info I was told that the 'D' shaped exhaust port floor conflict with the 1 3/4 SLP header, and cause a step in the header, and reuire slotting the flanges to raise the header slightly to match the D port on LT1 heads, since my headers are installed on the car, I think what I am going to do is change out the gaskets to get the pattern of the header port, and see where it falls on the LT1 head and if there is any major conflict in them, I do not believe in just throwing them on the car and asuming they will match, as I have the heads off the motor, and may pull the headers and check them out that way, I intend to port match the heads to the SLP headers any way, just looking for past info on them.

 

not on the 1 3/4 only the 1 5/8th. 1 3/4 are bolt and go.

 

Thanks for the info, I knew there was something different with one of the two sets of SLP headers, and still plan to port match them.

 

Jeff
Thats what I did. I origionally didn't port my headers. I got the carbon mark off of the header flange and opened up the header port with a carbide cutter. I then switched to earls dead soft header gaskets with the metal surrounds around the gaskets. these have proven to be leak free for the last 8k miles. my heads are max ported so the ports may be a little larger than stock.
Hope this helps,
Kory

 

Thanks for the info, as I will pull gaskets this week to see how they look.

 

I used these headers on my LT-1 swap. They really are a quality piece and fit great. I did need to add 3 washers between the engine and motor mount on the left side of the engine to get some clearance from the steering column. I probably could have used 2........But I didn't want to dent the headers to gain clearance..........SLP also said I could have installed new motor mounts............Next time it's out I might just do that.........