CK5
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‘76 K5 LS swap fiberglass body
- Thread starter Asherk5
- Start date
Factory 25-31 gallon tank from the blazer.
Over Christmas break we started reinforcing the floor since we didn’t like how some of it was weak. Rear section is done but we ran out of resin and will have to get more to finish the front. We used 1/2” plywood and fully encapsulated it in fiberglass.
Wow. Never saw what one of the fiberglass tubs looked like from that angle.
Stupid question time. I’m curious if you are putting this much extra work into reinforcing the tub, is the basic version you buy worth running without all this?
I know you don’t look to be done yet but overall do you think it’s still better to go rework a few fiberglass tub or full on rust repair with floors, rockers,doors and quarters?
I can totally see going the way you did if you have prior experience with fiberglass and all the ins and outs of it. Doing a great job so for. Just asking for the curious that would be on the fence of rust repair versus total tub replacement with a fiberglass unit.
Just saw this, awesome project!
Did you by chance weigh it as it arrived from US Body before you started adding to it?
I saw a few people asked and you mentioned you had scales, but I couldn't find the answer. I have been contemplating this myself vs just getting a blazer tub, but I would mainly do it for weight (the fiberglass). So if the whole tub is only 100 lbs lighter then I would be pretty dissapointed, but if you can save 300-400 lb's or something, that's significant. I would be very grateful for an answer there.
One other thing, is it possible with the fiberglass tub to keep the old mechanical vents down by the footwell that let air in through the cowl? I'm assuming that cavity is no longer hollow?
Did you by chance weigh it as it arrived from US Body before you started adding to it?
I saw a few people asked and you mentioned you had scales, but I couldn't find the answer. I have been contemplating this myself vs just getting a blazer tub, but I would mainly do it for weight (the fiberglass). So if the whole tub is only 100 lbs lighter then I would be pretty dissapointed, but if you can save 300-400 lb's or something, that's significant. I would be very grateful for an answer there.
One other thing, is it possible with the fiberglass tub to keep the old mechanical vents down by the footwell that let air in through the cowl? I'm assuming that cavity is no longer hollow?
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Its still worth it to me as I HATE rust repair and intend to keep the truck long enough that I would have to worry about it again someday... Covid was another concern with getting good replacement parts to weld in. it took us 3-4 months to get doors.
I did not expect to do all the work we are doing to the body (and others might not see the need) but id rather do it once and never have to think about it again. This would be perfect for someone who is building a mud truck or race truck as you wouldn't care so much about everything looking stock or as reinforced like I do.
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I did not weigh the body as it arrived. I do have scales and weighed the truck before swapping the LS and after. Once we get the fiberglass body back on the frame, I will post up final weights. I can tell you that 3-4 guys can pick up the whole fiberglass body whereas the steel body would not be possible.
We are integrating the original floor vents into the body and they will be functional. I'll post info of that when we get there.
When we are done, nobody should be able to tell this is a fiberglass body until they crawl underneath it.
Thanks, I look forward to the weight info, just let us know how much you think you added to the body with the steel and plywood.
BTW, was it required to add all that dash stuff to the cab to make the cowl vents work, or would they work if you just put the factory vent flappers in the fiberglass? I couldn't really tell from the pictures if the top cowl portion was hollow.
BTW, was it required to add all that dash stuff to the cab to make the cowl vents work, or would they work if you just put the factory vent flappers in the fiberglass? I couldn't really tell from the pictures if the top cowl portion was hollow.
The dash structure would not be needed to make the vents work, however the inner firewall portion would be needed... The fiberglass in that area matches what you see from the engine bay side of the original body, but there is another layer of steel that creates the "pocket" you are speaking about. See arrows in snap.
Ok, I thought it appeared that way, but I couldn't tell for sure, and the US Body mentioned cowl vents, so it wasn't clear, thank you for clearing that up. 
We finished up the fiberglass last weekend and are working on the last required details before applying lizard skin to the underside. Trimmed the firewall parting flange and glued seam together. Glued tunnel cover nuts/brackets and wiper motor reinforcement in. Finished filling the A pillars with structural foam.
I also started the painful process of cleaning up and removing all the dents from the trim.
I also started the painful process of cleaning up and removing all the dents from the trim.
Damn, that's a lot of vise grips!
We got the firewall painted and are refitting the front clip on this weekend. It’s starting to look like a truck again! I pulled the trigger on a new intake from summit and stand-alone harness from PSI to clean the engine bay up.
It looks real good!
If you ordered one of those overseas fabricated Summit LS intakes that's a copy of the Holley Sniper Intake I don't recommend those, they will kill a lot of torque and HP throughout your entire useable RPM range most likely.
If you ordered one of those overseas fabricated Summit LS intakes that's a copy of the Holley Sniper Intake I don't recommend those, they will kill a lot of torque and HP throughout your entire useable RPM range most likely.
Folkenheath, good info on the intake compare and I agree with your comments!
However, the stock 6.0 is likely close to double the power output of the tired 350 that used to be in the truck. The intake and harness are solely aesthetics rather than power for this build.
However, the stock 6.0 is likely close to double the power output of the tired 350 that used to be in the truck. The intake and harness are solely aesthetics rather than power for this build.
It does look pretty sweet.
I'm not one that can give up performance for looks, but if you don't mind, then nevermind. The whole build is awesome so keep up the great work! I look forward to seeing more.
