# Butler 461 Stoker Build



## GTO44 (Apr 11, 2016)

Since most of you guys in here appreciate pontiac builds i figured i’d start a thread on a build that’s been coming together over the last year. (I know its not a for a gto, tempest ect. but still a pontiac )

I’ve got a customer that has a ‘77 trans am with a horribly slow 400 motor that wanted a high horse power naturally aspirated pump gas setup.

He sourced a factory 1970 4 bolt main 400 block. We went with Butler’s billet main caps and an off the shelf Butler 461 stroker kit. The machine shop i used for this build (maximum machine) had to send it out to the only machine shop in the area that could align bore and align hone billet main caps. It took around 2 months just get that part done. Once back they set the block up, zero decked it and made some Pontiac specific oiling modifications. The owner of the machine shop has setup quite a few pontiac blocks for local List and bracket racers so we felt we were in good hands.

The stroker kit consists of a 4340 forged 4.250” Eagle crank, Eagle 4340 forged 6.800” H beam rods / arp2000 bolts, and Bulter/Ross forged 4.155” flat top pistons. The kit was only around $2,300.

We were going to go with KRE high ports but didnt want to run into issues with the factory shakerhood clearance. So we went with Butler’s Edelbrock round port castings with 87cc chambers, which are CNC ported to 340+ cfm. Compression ratio right at 10:1.

The intake will be a KRE Northwinds single plane. It is being port matched by Butler to the new heads and will be sent out to a different company to be converted to EFI multi port fuel injection.

We spec’d the cam with Ed Curtis at flow tech induction. Requirements being: Street/strip, 90% street driven with occasional track outings, don’t care about vacuum as we are going hydroboost with the brakes, don’t care about being rowdy, shift point around 6,500 and customer wants as much N/A power as possible from the combination and will also hit it with a 150shot at the track. Customers words, “I want this to be a bad bitch”. We were on the fence between a low lash solid roller and a hydraulic roller. Ed ended up going hydraulic roller. Here’s the specs:

Lobe lift: .399” / .399”
Duration @ .050: 245 / 259
Gross valve lift with 1.65 rockers: .658” / .658”
LSA: 112
ICL: 108

Lifters will be Johnson short travel link bars with heavy wall pushrods and dual valve springs with preferred seat pressure of 155#-160# on the seat. Not sure which valve springs Butler is choosing for the setup but ed recommends Pac 1207x or 1222x or Lunati 73925. Butler is currently setting the heads up now as they were waiting for the final camshaft specs. We’ll also be installing a set of lifter bore braces from butler.

Engine management will be a Holley Terminator X Max Multi port fuel injection setup with 60# injectors, Wilson 1,287cfm 4150 throttle body and holley dual sync distributor.

Trans will be a stage3 built 4L80e good to 1,100hp electronically controlled by the Terminator X Max ecu with an FTI 3,400 lock up stall converter. Rear gearing is 3:42.

Nitrous will be a dry plate kit with additional fueling controlled by the holley system thru the injectors.

Engine will also have a Butler mechanical vacuum pump setup driven off the crank. We have already modified the system to fit with his factory A/C and installed it on his current setup. The A/C bracket and vacuum pump bracket share the same mounting holes on the passenger side head so the brackets had to be chopped up and re-welded.

Any guesses on what this combination will produce hp/tq wise? We were hoping to be around 650hp N/A. Customer would love to hit 700hp. I’m going to setup a race gas tune for him with more timing to try to get him close to that number. I told him either way this thing is going to produce so much torque on the street it’s going to be a scary ride regardless if its 600hp or 700hp... He said good. Scare me.

I’ll post pictures when i get a chance and as we progress thru the rest of the build. Thanks for reading!


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## Old Man Taylor (May 9, 2011)

My guess is that the cam will keep you from getting to 700 HP, but it might be close. 650 should be no problem. Again , that's just my guess.


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