[markrieb]

1965 Buick Skylark Convertible working on a 6.0 LS2/4L60E with BTR stage 3 cam and Circle D 3000 rpm converter from a 2005 GTO swap using Holley motor mounts and oil pan. Car is on Ridetech coilovers/Wilwood brakes, C5 Corvette tires and wheels and is low, but doesn't currently have any issues with the stock Buick 350 and 2.5" Magnaflow exhaust.

Looking for input or known issues on header clearance. Both ground clearance and under hood clearance to frame, steering shaft and sparkplugs.

Choices seem to be Holley/Hooker Blackheart, Flowmaster (also Holley), Dougs, Headman and Ultimate.

If long tubes seem to be an issue, I don't mind going to a mid length header, especially with the 2.5" exhaust. I'm not worried about getting the absolute last bit of HP out of the engine - this combo will be more than enough for a fun cruiser. I'd have been happy with the stock LS2, but got really lucky at U-Pull-It...

 

[RICH1965]

Nice looking car.

 

[Rancher Lee]

I'm not sure how much is different between early and late A-bodys for clearance but I have the Flowmaster scavenger elite LS swap headers on my 70' 408 LS (With Holley/hooker forward mounts). They hug the block pretty tight and the collectors are VERY close to the floorboards (1/2" of clearance) so there is plenty of ground clearance. The only thing I had to clearance/grind down is the passenger side "ear" that stuck out from the 4L80E near the starter. speaking of starter, plenty of clearance for the stock truck starter I used. I recently seen some of these on the Holley "ebay" pages for a great price as factory seconds/customer returns.

 

[Alwhite00]

I used ebay stainless shortys and had to dink one tube slightly for steering clearance. 10 years ago they only had the 3 bolt flange but now they have the v band that would be easier to install.

 

[Hotwire]

I'm running hedman 45216 longtubes and they hang really low, wouldn't recommend.

 

[396325]

Definitely use mid length, easy to install best ground clearance and also starter, oil filter and other maintenance is easier. Don’t get equal length primary pipe headers they are a pain to deal with.

 

[rpol78]

If you have the Hooker mounts, get the Hooker Blackheart headers and Hooker exhaust system. I mocked up the 1 7/8" long tube headers with their 3" exhaust on my 67 and the fit is great. They tuck up nicely and clear everything. In post 104 of my build thread is a pic of the exhaust and post 49 shows the collectors. I believe I've posted some other pics also either in this or other threads.

 

[senna]

If you have the Hooker mounts, get the Hooker Blackheart headers and Hooker exhaust system. I mocked up the 1 7/8" long tube headers with their 3" exhaust on my 67 and the fit is great. They tuck up nicely and clear everything. In post 104 of my build thread is a pic of the exhaust and post 49 shows the collectors. I believe I've posted some other pics also either in this or other threads.

^^^^ This, I'm running the same setup. The ground clearance simply put is not a concern, the fit, quality and and everything else is awesome. starter and oil filter access are not an issue either.

 

[wes migletz]

If you have the Hooker mounts, get the Hooker Blackheart headers and Hooker exhaust system. I mocked up the 1 7/8" long tube headers with their 3" exhaust on my 67 and the fit is great. They tuck up nicely and clear everything. In post 104 of my build thread is a pic of the exhaust and post 49 shows the collectors. I believe I've posted some other pics also either in this or other threads.

Did you use the forward or rearward motor mounts from Holley? I'm looking to swap a LS and a 5 spd TKO into my 64 convertible. Any issues with your PS box or pulley? I will be running a Borgeson PS box.

 

[rpol78]

I actually have both and both clear the steering box fine with the GM corvette accessory drive setup. I'm using a Delphi 600 steering box which I assume you're planning on running also.

I started with the forward biased but the Maggie TVS2300 was too tight on the hood so I switched to rear biased mounts. I had an L99 out of a camaro which naturally had the gen 5 camaro balancer. Now I'm looking at an LSA style setup for my "LSA 396" so I moved back to the forward biased mounts.

There are three different balancers for the LS series - the LS1 version, the corvette version, and the truck/gen 5 camaro version. Corvette is the shortest, LS1 is second, and truck/gen 5 camaro is the tallest. The LSA balancer has the same drive locations as the corvette balancer for the first two belts. I haven't worked with the LS1 balancer.

If you're planning on running a low passenger side A/C compressor then you have to be more selective. If you have the truck style balancer then you can run either forward or rear biased mounts and a truck A/C compressor/mount bracket. You have to space the main bracket out to align the corvette accessories with the truck balancer. The holley spacer works for this. If you're running the corvette or LSA balancer then you need the forward biased mounts and an early CTSV compressor/mount for the compressor to clear the main cross member.

For A/C compressors the early truck compressors and the early CTSV compressor are both fixed displacement.

Which balancer are you using?

Here's the accessory drive I'm using:

https://www.summitracing.com/parts/nal-19421445

"LSA 396"

https://www.chevelles.com/cdn-cgi/image/format=auto,onerror=redirect,width=1920,height=1920,fit=scale-down/https://www.chevelles.com/attachments/engine-mock-up-jpg.715388/

 

[wes migletz]

@rpol78, thank you for the detailed post. This helps simplify it. I do not have an engine yet. I am leaning towards a L92 with a stage 1 or 2 truck cam and a passenger car intake. I also have access to a LSA Blower with a ZL1 lid, it is currently on a cammed L92 in our 70 Blazer. I don't have a drive system for the Blazer yet, but I pinned the truck balancer.

 

[rpol78]

You're welcome. I've been doing mock up on my '67 for awhile. Hopefully I'll get it moving forward again. I need to sit the engine in and figure out where I'm going to put the intercooler pump/tank, catch can for the engine, catch can for the radiator, cold air intake, flex fuel sensor, etc.