1981 GMC Sierra Classic 408 Striker swap - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Farmboy94 · 03-18-2018, 05:41 PM

I have an 81 Gmc that decided I wanted to swap an ls into and initially landed on a 5.3 and found a whole truck that I was going to pull the engine and transmission out of and swap into my 81. But then I got to talking with the guy that was going to do the machine work on the engine for me and he though I'd be better off, with the power level I wanted, going with a Blueprint 408 stroker, and after pricing everything out, I agreed. So I have a couple of questions that I have not been able to find answers too.

1. Since I already have the entire truck sitting in my yard, and I need accessories and brackets, will the accesorries and brackets off of that 2003 lm7 fit on this ls 408 stroker?

2. Would I be better off building the 4l60e from the donor truck and putting it behind the stroker or finding a 4l80e? I want overdrive for this thing, otherwise I'd just find a th400 to throw behind it.

3. Would everything clear accessory wise, frame rails, hood, etc.?

Oh and both the 81 and the 03 donor truck are 2wd, just fyi.

Thanks in advance for any help!

Bandit130 · 03-18-2018, 05:57 PM

Mattchu60 · 03-19-2018, 08:40 AM

I dont know the answers on the accessories - but I would think they should fit since they would both be "LS" type engines - I have to think the mounting points are common.

I would say a 408 LS would want a 4L80E. That thing will make a lot of hp and torque - 4L80E would just handle the abuse a lot better. I'm working on a 6.0 swap and going to use the 4L80E for peace of mind.

RotaryRocketeer · 03-19-2018, 10:29 AM

Everything should bolt up to the stroker block and clear, except for MAYBE the A/C. Depending on the mounts you use to secure the LS block, you may have to find a way to go with a top mount compressor. Lots of aftermarket mounts, especially adjustable ones, inhabit the same space as the low mount stock compressor.

Another vote for the 4L80E here. The 60 is akin to hot garbage when put behind something stout.

Tom · 03-19-2018, 05:21 PM

A 408 stroker and 325 stocker are no different on the outside.
They didn't even put 4L60's with stock 6.0's, are you crazy?

03-18-2018, 05:41 PM	#1
Farmboy94 Registered User Join Date: Nov 2017 Location: Nebraska Posts: 1	1981 GMC Sierra Classic 408 Striker swap I have an 81 Gmc that decided I wanted to swap an ls into and initially landed on a 5.3 and found a whole truck that I was going to pull the engine and transmission out of and swap into my 81. But then I got to talking with the guy that was going to do the machine work on the engine for me and he though I'd be better off, with the power level I wanted, going with a Blueprint 408 stroker, and after pricing everything out, I agreed. So I have a couple of questions that I have not been able to find answers too. 1. Since I already have the entire truck sitting in my yard, and I need accessories and brackets, will the accesorries and brackets off of that 2003 lm7 fit on this ls 408 stroker? 2. Would I be better off building the 4l60e from the donor truck and putting it behind the stroker or finding a 4l80e? I want overdrive for this thing, otherwise I'd just find a th400 to throw behind it. 3. Would everything clear accessory wise, frame rails, hood, etc.? Oh and both the 81 and the 03 donor truck are 2wd, just fyi. Thanks in advance for any help!

03-18-2018, 05:57 PM	#2
Bandit130 Registered User Join Date: Dec 2014 Location: Euless, Texas Posts: 510	Re: 1981 GMC Sierra Classic 408 Striker swap __________________ 1974 Cheyenne 10 LWB Stock 350 W/HEI /TH350/AC/4 BBL Quadrajet Mopar by Birth Chevy by Choice

03-19-2018, 08:40 AM	#3
Mattchu60 Registered User Join Date: Jan 2014 Location: Swaledale, IA Posts: 484	Re: 1981 GMC Sierra Classic 408 Striker swap I dont know the answers on the accessories - but I would think they should fit since they would both be "LS" type engines - I have to think the mounting points are common. I would say a 408 LS would want a 4L80E. That thing will make a lot of hp and torque - 4L80E would just handle the abuse a lot better. I'm working on a 6.0 swap and going to use the 4L80E for peace of mind.

03-19-2018, 10:29 AM	#4
RotaryRocketeer Registered User Join Date: Jul 2017 Location: OKC, OK Posts: 247	Re: 1981 GMC Sierra Classic 408 Striker swap Everything should bolt up to the stroker block and clear, except for MAYBE the A/C. Depending on the mounts you use to secure the LS block, you may have to find a way to go with a top mount compressor. Lots of aftermarket mounts, especially adjustable ones, inhabit the same space as the low mount stock compressor. Another vote for the 4L80E here. The 60 is akin to hot garbage when put behind something stout.

03-19-2018, 05:21 PM	#5
Tom driving is in my blood Join Date: Dec 1999 Location: Mesa AZ Posts: 5,690	Re: 1981 GMC Sierra Classic 408 Striker swap A 408 stroker and 325 stocker are no different on the outside. They didn't even put 4L60's with stock 6.0's, are you crazy? __________________ -78 c10 short/step: 388cid, M20, 5/5 drop, lots more. Playtoy and first vehicle. -98 c1500 x-cab: 5.7L, 17" rims, 5/6 drop, flowmaster, helper bags,NBS rear disk brakes. -02 Suburban 4x4: leveled front -CBR600F4i, CBR600RR, CBR1000RR, and standup skis DISCLAIMER: I cant spell for the life of me.



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