What block do i have 2 bolt or 4 bolt

[aussiesteve]

i have a 1993 GMC 2x4 extra cab. 5.7 Tbi 4L60E
its a 350 chev we all know

would this be a hydraulic roller cam engine
would this be a 2 or 4 bolt block
would it be a one piece rear seal block
It does have center bolt rocker covers but has the standard bolt patern on the intake like an old 350 from the 80,s or 70,s.

looking at starting to aquire engine parts to do a mild 383 with parts i have from 2 other motors. it will be transport only not a weekend worrier.
vehicle has a brand spankin 4l60e and i hate that short 1st gear,, a 4l80 will go in also.

 

[kennythewelder]

1500 trucks were 2 bolt main. Only 3/4 and 1 ton trucks had 4 bolt mains, on GMT 400s. Yes, it is a 1 piece rear main seal, and I think they are all roller lifter motors. None have roller rockers. Vortec had much better heads. The first Vortec 5.7 in a GMT 400, come out in 96.

 

[GoToGuy]

Roller lifters were standard with Vortec, '96 and beyond. Not TBI engines. My 95 is original and had the intake off , no rollers lifters. There are rumors of some TBI had roller lifters , not that I've seen or anyone saying they've seen any.

 

[kennythewelder]

Roller lifters were standard with Vortec, '96 and beyond. Not TBI engines. My 95 is original and had the intake off , no rollers lifters. There are rumors of some TBI had roller lifters , not that I've seen or anyone saying they've seen any.

Yeah, I wasn't sure about the roller lifters in a pre Vortex.

 

[Sean Buick 76]

Yeah, I wasn't sure about the roller lifters in a pre Vortex.

Some of the TBI blocks had the provisions for roller lifters while others didn’t.

I wouldn’t worry about a 2 bolt vs 4 bolt main unless it’s making over 450 Hp. Even then people have been known to make 600+ Hp with the 2 bolt main blocks.

If you get the casting number you should be able to determine if it’s a roller block or not.

 

[GoToGuy]

My block has the risers in the center, no machining.

 

[Sean Buick 76]

My block has the risers in the center, no machining.

Yes any TBI truck block that has the risers will still need to be drilled and tapped for roller use. Interestingly the car TBI engines were all rollers after 1988 I’ve been told. Correct me if I’m wrong.

 

[L31MaxExpress]

There is no set way to know what you have without opening it up. Some are 2 bolt and some are 4 bolt. Some are roller cam blocks without roller cams, some have roller cams and yet others have no provisions for the roller hardware. There are general rules of thumb but nothing concrete especially on a 25+ year old truck that may or may not even have the engine it was born with now.

 

[aussiesteve]

The reason i ask 2 or 4 bolt is i have 2 vehicles
1 82 z/28 that i had a 400sbc in and brand new L31 vortecs and a Th350
car ran 13.0 on street tires.
i since bought a 383 from America and we dumped the hyd roller and put in a lunati solid flat tappet deal and picked up 76hp.
Afr 195s etc
i then put the camaro in storage after it was painted and bought the 1993 GMC and the poor old 350tbi needs a rebuild.

i can freshen up the 400 i have spare and put the vortecs back on it and run a spare 750 vac i have,, with 10.5 compression it will be ok in the truck.

OR i pull the camaro 383 and put it in the truck and use the Truck block to build a hotter 383 for the camaro as the one in the Camaro is lame and only runs 75% of what it should.

The Truck can either used the 400 sbc i have or i put the camaro 383 in it and have the truck original 350 rebuilt and get the 520hp 500tq i originally wanted for the Camaro. the only thing i would need is the block from the truck. If its 4 bolt a 4340 assembly and dart pro heads will go on it. I am not interested in LS conversions in either car.
I am in Australia and used Ls engines are $5000 to start with a worn out LS2 plus all the bits to fit it,,,, NO THANKS.
the truck will get 400hp either way i go and its a rust free vehicle you dont see here.

We dont do Hyd Roller cams here as the lifters are junk unless you pay $750+ for quality. and good builder here wont touch them.
Either way the 4L60E i just had rebuilt will come out or my truck and a 4L80E will go in as the 1st gear on the 4L60 is terribly low. I didnt know the 4L60e was nothing more than a T700R4, and its basicly a 6cyl gearbox. Mine had Sonnax internals fitted on the rebuild and its ok with the stock 350tbi, but i hate it. lol

 

[aussiesteve]

By the way,, just an interesting thought
Apparently trucks made in Canada were not sold new in America!

My C1500 GMC was made in Ontario Canada, it ways on the sticker inside the front door on the pillar.
The original books say it was sold New througn Mc Fersons in Carson California 1993, bought used in California in 1997 and bought to Australia and changed to Right Hand Drive in 2000. I bought a mechanically poor vehicle but have parts and bought a lot locally from importers and a lot on line from America. The engine will be next then a FULL repaint the original colour and lower it with new wheels.