Radically altered yank and the dreaded IVA

[Rustykipper]

Morning chaps, this is for any IVA experts out there, no idea where to post this but as it’s a yank this would be a good starting point.

Ok, I’ve got an 1984 S10 blazer 4x4 that’s been in the family for over 20 years and over this time has gained a 5.7L V8 in the place of the tired old 2.8l V6 together with a matching 700R4 auto, it’s not so much a daily driver but gets used every weekend all year round. With regards to the V8 my interpretation is that this makes it ‘substantially changed’ (I think it might be 15% more powerful than original), as there are no body or chassis modifications I understand this just means I don’t get free road tax when the vehicle hits 40 and have to carry on having MOT’s, I’d rather enjoy the V8 and forgo the free tax and would prefer to have the yearly MOT as I put spanners to it myself. I have a Chrysler 8.25 rear axle going in soon to give me rear discs and more strength but this will still keep me above 8 points unless I’m misunderstanding something.

Now here’s the thing, I plan to carry out a solid axle conversion which involves removing all the front suspension and replacing it with a Jeep XJ front axle hung off a pair of leaf springs (coilover shocks in the future) and 32 inch tyres, this will take me well below 8 points not to mention modifying the chassis, this definitely makes it radically altered. I could just do it and keep quite but don’t want to spend the rest of my days looking over my shoulder anyhow it seems the DVLA are now actively looking into modified vehicles so would only be a matter of time.
This will then mean re-registering the truck and going for a (B)IVA. I’ve read through the IVA manual a few times but I can see a few issues I’m not 100% sure about.

1. Engine. I don’t have either a receipt or proof of age for the engine, I know from the date stamped on the main bearings it’s a 1986 lump. I guess worst case it has to be tested to 1996 standards? Not a biggie as the last emission test it passed with 0.01% CO and 350ppm HC, a bit of carb and timing tweaking should get it through, I believe Q plate motors don’t require an MOT emission test thereafter.

2. Glass, windscreen is not a problem as it was replaced about 20 years ago and is E43R marked, side glass could be a big issue, its matked DOT and tempered but the IVA will only accept E marked glass. I could probably get the two side windows made by Pilkington but the rear side windows are HUGE. I’m kind of thinking about panelling over them kind of turning the truck into a van just for the test. If I knew they would come out in one piece I could substitute some sheet steel and then refit them or possibly sell them on and replace with E marked Perspex / polycarbonate.

3. Rear 3 point seatbelts, the current bench seat has built-in retracing lap belts (2 point). The only way I can see to fit retracting 3 point belts is to fit a rear roll cage similar to a mk2 Frontera and mount the mechanism to it. I’m thinking a 2.5 inch CDS steel hoop bolted to the wheel arches with load spreading plates and gussets and then a couple of triangulation legs bolted to the load space floor behind, it would be way strong enough (I’m well known for over engineering everything!) any thoughts? Can I retain the 2 other mounts built into the seat? I think a roll cage in the back would look pretty awesome!
Probably easier to permanently remove the rear seat but I really don’t want to do that.
I believe I’m likely to require rear head rests also.

4. The floorline cone thing test, my front spring mounts will be directly under the bumper, these will definitely get fouled by the cone, I guess the only thing to do is to temporarily move the front bumper forward.

Sorry for the long post.


p.s. I did post some more pictures but as yet can't get them to show.

Edited by Rustykipper on Wednesday 30th May 12:39

[Rustykipper]

Thanks guys.

The rear glass is bonded and probably structural, I can’t believe it will come out without a fight.

The reason for the suspension change is kind of threefold.

1. The standard independent suspension is absolute pants off road due to minimal travel and small tyres, and the aluminium front diff is not up to the power of the V8.

2. The truck drives like a dream on the road, the handling is really tight for a truck and the V8 makes it a pleasure to drive but driving around the broken, rutted and cobbled streets of Sheffield is literally like falling down the stairs, by half way down the fun as gone out of it and you just want it to stop. I’ve had bulbs shake out of the dashboard, glass falling out, lights falling off and once I had the dog in the back, oh lordy, think pinball machine……he was not happy, he runs away and hides now every time I open the garage door! I’ve had new rear springs made since which has softened the rear a bit.

3. I want to fit some bigger rubber but 28 inch is about as big as I can go without a hugely expensive lift kit or a body lift which in either case I’ve still got the limited travel of the IFS suspension, also the torsion bars seem to be almost impossible to find so once one of those snap its game over.
What our American cousins do is simply hack off the existing suspension and fit an axle and springs usually from a grand waggoneer then Bobs your uncle Fanny’s your aunt. Not so easy over here.
Also the solid axle has the benefit of 12 inch discs and 2 pot callipers to counter the bigger rubber.

The glass is purely tick box bureaucracy. The IVA manual lists American, Canadian and Japanese comparable standards for glass, in the case of American its ‘FMVSS 205 (U1)’ however it goes on to state the glass must have the marking ‘E 43R’ from the original manufacture and then states there is also a mandatory marking to be shown indicating the type of safety glass (l,ll,lll,lV). So temped to engrave something on the glass but might end up doing 5 years porridge! The glass is original and perfectly safe, the only difference from UK glass is the missing markings.

We had a similar problem at work when we built some plant for the US, the UL inspector refused to sign the unit off as it didn’t have ‘UL’ printed on the cable (big inch and a half thick cables), we had all the certificates for the cable showing the certifications but we had to pull all the cables out and ship new cables over from the States, Then the CSA inspector (Canadian) turned up and went against just about everything the American inspector specified…….. thick end of million quid lost through bureaucracy and 5 years on the plant still sits in a corner of the car park and the project manager retired due to nervous breakdown!

I had a quick look at Rockauto last night to see if my 1st gen S10 had the same part number for the front side windows as the later Blazers that were sold in Europe but they look to be different.
I have both axles prepped and laying on the garage floor, if this was a land rover or something easily replicable I would maybe take the risk but I’ve had this truck well over 20 years so kind of attached to it. Someone sensible might cut their losses and go with a body lift…..
Probably worth ringing one of the local test stations and asking the question but don’t want to flag anything up.


Edit. I've just noticed the IVA test manual states "Non-European and Other Acceptable Standards" yet the glass must be E marked...... a bit of a contradiction going on here....confused!?

https://assets.publishing.service.gov.uk/governmen...page 25

Edited by Rustykipper on Thursday 31st May 15:19

Edited by Rustykipper on Thursday 31st May 15:21

[Rustykipper]

Hey Moose, any idea if the torsion bars are still available new over there? These trucks are like hens teeth in UK wrecking yards. I think part of my problem is the bars are just plain tired and the weight of the V8 is compounding the issue, if I jack the front of the vehicle I'm getting almost no down travel on the suspension.

Oh, for the 12 inch discs I've done a WJ knuckle conversion, this gives me full crossover steering as well as huge brakes, I had to ship the knuckles from Germany as they need to be left hand drive. The rear axle is from a Jeep liberty and that has even bigger rotors.

The interiors not bad, the rear seat area is like new, the driver and passenger area are a bit tired and cracked, the top of the dash is quite bad, these trucks are a celebration of man made materials! The quality of plastic quite laughable but the mechanics are crude and easy to fix and the chassis will last a thousand years, its over thirty years old and almost like new

I have considered fitting an iron front diff from a Bravada but would have to get it shipped over, if I went that route I would swap in a full time transfer box and go AWD, it might limit all the embarrassing wheelspin!

A better bet for rough roads might be to keep the IFS but go with coilovers, essentially a pre-runner setup but again I will run out of points and have to submit for the IVA test.

[Rustykipper]

Thanks again Moose.

It looks like all the torsion bars have been discontinued, summit racing have a single GMC Safari bar so might have a search for yard that has a second gen being broken, they were sold over here in small numbers, failing that I’ll try to get a pair shipped from a US breakers. I’m sure the second gens are significantly heavier than mine and they come with the 4.3L which must be getting on for the weight of the 5.7. I’ve offset some of the weight, battery relocated to load space, gear reduction starter and aluminium intake replacing the heavy cast iron original.

I’m kind of thinking about an IFS suspension lift (if still available), if its 100% bolt on and I’m just relocating the front suspension then I think I should scrape through on points. This will have to be a second gen lift kit that may need modifying for the 1st gen torsion bar mount, I think they stopped making the earlier kits donkeys years ago.

Failing that it will have to be a body lift, this should allow me to fit some 31 inch rubber. I might look at some softer riding shocks to take some of the harshness out of the ride, I’m sure 20 years back this truck was quite bouncy it seems to crash over potholes now.

I now need to try to find someone who wants a Dana30 front axle with WJ knuckles and all mounting hardware removed ready for leaf springs, I’ve lost a small fortune but at least still have the truck!